bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on the Buffer Material Used as Hip Protector for the Elderly against Falling down
Authors: Song Yi Lin , Zhang Tong , Gao Shu Mei
Published: August 2012

In order to develop an efficient hip protector to protect the elderly's femur when he (or she) has a fall, the research on characteristics of sponge material is carried out. The buffer rate of material is defined, and the material absorption ability to the instant impact is measured in this paper. An experimental device which can simulate the force state of femur hit by instant impact when the elderly is falling down is developed and used to research the buffer rates of different types of sponge. According to the result, the soft material is effective to absorb small impact, while the harder material is useful for absorbing greater impact. Meanwhile, the buffer rate also largely depends on thickness of the material. Results show that in the same hardness material, the buffer rate of 30mm-thickness is apparently higher than that of 20mm and 10mm-thickness. And, when thickness of the material increases, the sensitivity of the buffer rate to the material hardness and to the instant impact acted on the material decreases. That is, the higher buffer rate could be obtained in a large range of instant impact and hardness of material. This conclusion is very useful for us to select suitable material to make hip protector or other sport protectors.
Center Distance Change of Silent Chain Drive Effect on Sprocket Tooth Profile Modification
Authors: Sun Wei , Liu Xiao Lun , Liu Jia Jun , Zhang Wei
Published: August 2012

The principle of modified gear was applied to silent chain transmission, and tooth profile equation of the involute sprocket was derived, then method of processing gear using imaginary rack cutter solved modification coefficient of involute sprocket. When Center distance of silent chain drive changed smaller, processing method of sprocket modification coefficient and range of modification coefficient values were analysed. The method by changing the modification coefficient of involute sprocket solves the problem that the chain links are increased or decreased in the actual application to be unable to meet the requirements of specific center distance, thus improve transmission performance of silent chain.
Experimental Study on Pre-Stress Hard Cutting of Aero-Screw and its Machined Surface Residual Stress State
Authors: Liu Jian Ping , Ye Bang Yan , Qin Meng Yang , He Ai Dong , Shi Ya Ping
Published: August 2012

Pre-stress Hard Cutting, known as a new machining technology, is the combination of hard cutting and pre-stress cutting. Some reports show pre-stress machining can improve residual stress state of machined surface and prolong fatigue life of mechanical part, such as drive shaft, bearing and engine vane etc. Based on the principle of this technology, this paper take aero-screw shaft machining as object, investigated the pre-stress loading method, experimental device and implementation process of pre-stress hard cutting. Experiment is carried out for aero-screw shaft with PCBN tool, cutting force, machined surface residual stress state and distribution are measured. The experimental results show that by using this method, residual compressive stress is got on machined surface and good surface finish is gained, hence it can control machined surface residual stress state actively and improve the fatigue life of aero-screw shaft..
The Modal Analysis of Capstan Wheel of the JKM Type Multi Rope Friction Elevator
Authors: Luo Feng Li , Li Guang Yu
Published: August 2012

Based on the strong characteristics of comprehensiveness and practicality of the Mechatronics Control Engineering Class, a PBL based “One main line, Two links, Three practical points” teaching mode and methodology has been formed in 7-year exploring and practicing and has been applied in the teaching reform in mechatronics control engineering class at Beihang University. By implementing the method, excellent results have been gained and the teaching task has been accomplished well. It meets the requirement of cultivating innovative talents for the current social development and is worthwhile to be extended widely.
Design and Analysis of a Novel Micro-Angular Vibration Testbed Driven by Voice Coil Actuator
Authors: Zhang Zhi Yong , Zhou Qing Kun
Published: August 2012

The construction and the operating principle of the novel micro-angular vibration testbed (MAVT) are presented, the MAVT is designed to complete the angular performance testing for the micro sensor and parts such as MEMS-gyro, angular accelerometer. A systemic design procedure of the optimized flexure hinge and general voice coil actuator (VCA) to fine single-axis MAVT actuator are introduced for fast and precision actuation. A method for measuring frequency response function by means of a displacement sensor electric eddy current sensor is designed. To verify the performance of the designed MAVT, frequency response of the system are performed, the differential equation of the pull-tilting motion is established according to the Lagranges equation, the formula of the natural frequency is derived, and the model analysis of the MAVT is also carried out with the help of limited element analysis. The static stiffness experiments show that the angular stroke of the MAVT is 1° and preliminary tests performed on the closed-loop control system indicate that angular resolution of 1 can be achieved. Model experiments performed on the prototype of MAVT are presented and the theoretic result fits with the result of experiment (250Hz). For fast and precision actuation performances, design parameters are selected based on the dynamic model of VCA and flexure hinge, and design process is completed. The model results can be provided for the construction design of the MAVT. Conventional platforms of angular performance testing are bulky and costly. Analysis and experiments results indicate that the novel MAVT is an efficient platform to complete the angular performance testing for micro sensor and parts.
Vibration Model Construction of the CNC Embroidery Machine Based on the Timoshenko Beam Theory and its Experimental Research
Authors: Li Peng , Gu Li Zhi
Published: August 2012

With its technological development, the CNC embroidery machine rotational speed has increased dramatically. Consequent vibration and noise increase the disconnection rate in the embroidery process and affect the embroidery quality and production efficiency. To solve such problem, by analyzing the vibration causes and comparing the different characteristics of the Timoshenko beam and the Euler-Benouli simply supported beam, the current study indicated the limitation of the traditional vibration analysis method---the widely-used Euler-Bernouli simple beam theory, and constructed a vibration model based on the Timoshenko beam theory. Then a finite element model of the embroidery machine beam was built S and the corresponding experiment were done. Results from the constructed mechanical, mathematical model, and the ANSYS finite element model were compared. It has been verified that the constructed models are consistent with experiment results and that vibration models are constructed reasonably and feasibly. According to these models, the key parameters affecting the beam vibration are identified to work out more accurate and effective structure optimization design and prediction.
Motion Path Control of Multi-DOF Handling Manipulator in Industrial Field Based on Vision and C-Space Obstacle Avoidance
Authors: Chen Di Jian , Zhang Xiao Dong
Published: August 2012

In order to realize the intelligentization of the multi-DOF handling manipulator in the industrial field, this paper presents a motion path control approach which combines the vision based identification and localization and C-space (Configuration space) based obstacle avoidance planning. The objects in the image captured by CCD camera can be extracted by gray processing, background subtraction, binarization, and edge detecting, the work pieces and the obstacles can be matched based on roundness and squareness, and then the coordinates of above objects can be obtained by parallax and coordinate conversion. In addition, both the source and destination coordinates in C-space can be obtained by mapping these configurations position and orientation into C-space, and the motion path can be automatically generated by variable step A* search in free area which is built based on solid manipulator model, then the handling work can be finished and obstacle avoidance can also be realized. The results of simulation and experiment demonstrate the scientificalness and effectiveness of this control approach.
Study on Method for External Characteristics Extraction and Classification of Tomatoes Used for Grading Robot
Authors: Li Chang Yong , Cao Qi Xin
Published: August 2012

The color and shape feature are very important quality characteristic for classification of fruits. The dominant grading color histogram feature and radius normal angle histogram feature were presented in this paper. They can well represent the color and shape information of fruits respectively and are not sensitive to the changes of scale, translation and rotation. Experiment results showed both histogram features can effectively distinguish between different grade fruits and have high classification accuracy. They are suitable for real-time application.
Positive Analysis of a New Type of Planar 3-DOF Parallel Mechanisms
Authors: Meng Zhao Xin , Lei Xiao Gang , Zhang Chao Mei
Published: August 2012

The planar 3-DOF parallel mechanism was developed as a part of the pushing device for the wood sawing. Using closed vector polygon method to make positive movement analysis of the mechanism, establish the positive solution mathematical model. It provided the theory bases for the error analysis and control algorithm of the planar 3-DOF parallel mechanism.
Study on the Design and Analysis of Spindle System of NС Machine Tools Based on Digital Design
Authors: Sun Hui Juan , Yin Guo Fu , Mi Liang , Yin Yang
Published: August 2012

Aiming at these problems of complicated analysis, high repeated rate and resource sharing in the process of the NC machine tools design and performance analysis, a development platform is built to integrate the structure design, performance analysis, optimization of spindle and resource sharing. The platform includes digital design, 3D entity modeling and virtual assembly, finite element analysis and optimization, and dynamic simulation module. Each module can normally operate and exchange data by means of coordinating the interface between modules. The experiment shows that the developed system could effectively improve the efficiency of design and analysis of spindle, and could provide reference for the optimization design and the actual production manufacturing.
Study on Fuzzy Cluster in the Model for Rapid Identification of NC Processing
Authors: Li Xi , Feng Dan Feng
Published: August 2012

In this paper, a application of signal identification by using fuzzy cluster is studied Based on the one order T-S model, an algorithm for online establishment the nonlinear model between the servo current and cutting force is presented by fuzzy likelihood function to derive fuzzy cluster. Finally, the experimental study has been given. The result showed that it can be regarded as a good dynamic identification algorithm for intelligent control of NC processing.
Distributed Control System Based on PIC Microcomputers
Authors: Zhang Xiang , Pan Xu Dong , Wang Guang Lin
Published: August 2012

This paper describes a distributed control system, which is based on PIC microcomputers. The hardware of this system included industrial personal computer, RS232-RS485 converter, control circuit, motor driver and so on. The PIC microcomputers on control circuits are used as basic control chips. The software of system is developed by Visual C++, communicates through the RS485 bus. The human-machine interface is developed, which is intuitive and friendly. Test result shows that the control system is effective and reliable.
Test Verification and Design of Zero Position Deviations Parameter in Electric Actuator System
Authors: Wu Gui Cheng , Liu Yu Hui , Liu Hua Feng , Yang De Liang , Deng Jian Hui
Published: August 2012

During the debugging of electric actuator system and aircraft pose control, the electric zero position of electric actuators need complicated adjust because of the existence of machining error in machine after electric actuator system is restart. This paper proposes a on-line parameter configuration method, develops a status parameter memory system of electric actuator system. The system take XC3S400 as core chip and AT24C02 as memory chip, save the state information about electric zero position regulated parameter, important control parameter, and etc. Through on-line parameter configuration, we can abridge the adjustment step of electric zero position which happens in after the electric actuator system is switch off and restarted, simplify operation difficulty, saving time, and improve quickly responding ability of system.
Research on the Impact Control Performance of the Space Manipulator under the Noncontact Impedance Control
Authors: Chen Zhi Gang , Wu Cui Ru , Zhang Guang Yu
Published: August 2012

This paper proposes the noncontact impedance control which can realize the control of the impact which happens between the space manipulator system and the target in capturing operation. And the impact value is influenced by the impedance parameters of the noncontact impedance control. The paper conducts the simulation of the effect of the impedance parameters on impact control performance and concludes the impedance parameters' preliminary coordination principle.
Urban Road Traffic Sign Recognition Algorithm Based on Monocular Vision
Authors: Yu Xue Cai , Chen De Ren
Published: August 2012

Intelligent Transportation System (ITS) is a new industry and development greatly in recent years. The advanced electro-communication and computer technology combines detection, control, active warning and other information means. It provides a great guarantee for improving traffic safety and high efficiency. This paper puts forward the traffic rate-limiting sign and Lane Mark recognition method. In this study, four steps are applied to recognize a traffic and Lane Mark sign in an image. The first step, we transform the color space of image from RGB into HIS. Then the image blended HIS and RGB information is segmented. The third step, the text restrain and eliminate the isolated noise point based on eight-neighborhood. Finally, the traffic speed-limit sign and Lane Mark is recognized with template match. Our experiment results, in the out door, show that the method mentioned in the paper is useful and effective.
Research of Target Recognition Based on Active Shape Model
Authors: Peng Hong Xing , Zou Xiang Jun , Xiong Jun Tao , Guo Ai Xia , Chen Li Juan , Wu Ding Zhong
Published: August 2012

The problem of robot operation based on vision is to locate and identify the target. The approach of active shape model has been used to identify the target and taken citrus as example in this article. First, the different shapes of citrus are calibrated and calibrated; Second, the method of principal component analysis is used to get the models of different shapes of citrus; Finally, the models are used to do gray matching with the actual citrus and the characteristic parameters such as the ratio of pixel to number are extracted to achieve the identify of the citrus image. The experimental results show that the method has higher recognition rate for citrus image and better robust and good flexibility.
The Optimization System Design and Experimental Study of Process Parameters Based on LabVIEW
Authors: Yue Wen Hui , Chen Xue Hua , Wang Xiao Jun , Weng Jian Xin , Han Zi Qiang
Published: August 2012

With putting the response surface methodolody and design theory into the programming of LabVIEW8.6, the process parameters optimization system is designed. The system can realize the function of test project design,online data acquisition, response surface model building and process parameters' optimization, which can greatly reduce the calculated amount of modeling and optimization. Taking 45 steel milling experiment for example, the models of surface roughness and cutting force are established by using the optimization system, taking the minimum surface roughness value as target and optimizing the process parameters, which provide practical support tools for further analysis of process parameters on the effect of processing quality
Based on the Sensor Network and Virtual Instrument Circuit Board Reliability Test System
Authors: Chen Sheng Yi , Wang Gui Tang , Li Ying Ge
Published: August 2012

Aiming at the problem that the quality of fans control circuit board is not stable, this paper designs and develops of multiparameter networked reliability testing system of eclectic fans circuit board based on the virtual instrument Labview. This system adopts distributed structure, which consists of three parts: the measurement and control node, virtual instrument PC, interference sources. The sensing nets measurement and control node with embedded processor, controls test model,process,jamming signals voltage and frequency of circuit interference source, and real-time online collects parameters of control circuit boards key components on operation process ,such as, voltage and temperature, and then through the sensor network sends those dates to Labview virtual instrument machine. The Labview software does display storage, and comprehensive analysis of operation. The application shows that the system can accurately and rapidly acquire circuit board components parameters, operate stably and reliably, and play an important auxiliary function to find the products quality problem and improve the circuit board design.
Design and Simulation of Tobacco Harvesting System Based on Virtual Manufacturing Technology
Authors: Liu Jun , Ma Wen Kui
Published: August 2012

Virtual manufacturing reflects the nature of manufacturing in the computer implementation. It is the comprehensive development and application of computer simulation technology and virtual reality technology in manufacturing. It is also a new concept in manufacturing industry, for which enterprises use information integration as bases. This article therefore describes the practical applications of the tobacco harvesting in virtual manufacturing system. Based on the whole to part-based design idea, we adopt a brand new design method which uses the interaction of three-dimensional design, graphic design and partial tests. Meanwhile, it uses soliderworks software to create three-dimensional modeling and motion simulation for the tobacco harvesting system. Specifically, for the design part, we first conduct the constraint and connecting assembly of the established three-dimensional model of the tobacco harvest system to form an entirety. Then we carry on the motion simulation tests, which show the kinetic characteristics of the system in the virtual environment. The final step is data processing and error modification. The result indicates that this method not only improves the accuracy and efficiency of design manufacturing and reduces relevant costs, but also improves the collection level of the leaf tobacco harvesting machine, reduces harvesting costs with a relative high value.
The Development of Parametric Part Library Based on WEB
Authors: Wang Hong Wei , Sun Wen Lei , He Li , Li Peng Cheng
Published: August 2012

To meet the need of sharing three-dimension model among different CAD/CAM software users and enterprises, and to realize the functions of parameterizing three-dimension model, managing and expanding the data in system, a system of parametric part library is developed by using the technologies of secondary development for CAD/CAM software, ASP.NET, Database and Web3D comprehensive. This paper gives the way and process of realizing the functions above, and an instance of system is given in the paper.
A New Fat-Model for Large-Scale Product Assembly
Authors: Bao Jin Song , Wu Dian Liang , Ye Jin
Published: August 2012

Large-scale component assembly, such as the installation of aircraft wings and ship section etc., is usually high cost, long cycle. Virtual assembly simulation gives the possibility of direct and visual perceive of assembly before the actual assembly using digital prototype. A new virtual assembly model, called VAFM (Virtual Assembly Fat Model), is presented. It integrates not only geometry data, but non-geometry information is embedded. All information of model will evolve, mature and derived gradually, from thin to fat, during the whole assembly process. The paper gives the definition of a VAFM, its framework and the evolution rules of the fat model. Meanwhile the paper design the modeling language based XML. Finally, the visualization of VAFM is also presented..
A Principal Component Analysis Based Fault Detection Method in Etch Process of Semiconductor Manufacturing
Authors: Yang Jun Gang , Zhang Jie , Yang Jian Xiong , Huang Ying
Published: August 2012

A Principal Component Analysis based Fault Detection method is proposed here to detect faults in etch process of semiconductor manufacturing. The main idea of this method is to calculate the loading vector and build the fault detection model according to training data. Using this model, the main information of fault data can be obtained immediately and easily. Also the principal component subspace and residual subspace can be constructed. Then, faults are detected by calculating Squared Prediction Error. Finally, an industrial example of Lam 9600 TCP metal etcher at Texas Instruments is used to demonstrate the performance of the proposed PCA-based method in fault detection, and the results show that it has such advantages as simple algorithm and low time cost, thus especially adapts to the real time fault detection of semiconductor manufacturing.
The Application of Second Development Technology for SolidEdge in Web-Based Parts Library
Authors: He Li , Sun Wen Lei , Wang Hong Wei
Published: August 2012

One of the purposes of building a web-based PLIB is to transform the CAD technology application from isolated environment to network. To realize the main function modules of web-based PLIB system, the object hierarchies of SolidEdge and its Second Development Technology under .NET Platform are studied. And on this basis, the implementation methods of these function modules closely related with the SolidEdge API (Application Program Interface) are detailed, including the dynamic browsing of three-dimensional part model, the online parametric design of part, the information acquisition of part property. At last, an application instance is presented.
Assessment of Implementation Capability for Design-Manufacturing Integration Based on Support Vector Machine
Authors: Chen Song , Tian Ye Zhuang , Yang Yang , Yan Liu
Published: August 2012

Design-manufacturing integration is one of the most signicant contemporary trends in new product development (NPD) for manufacturing enterprises. Exploring the implementation capability of manufacturing enterprises through the assessment of design-manufacturing integration is an important and crucial step for determining what kind of design-manufacturing integration is appropriate for manufacturing enterprises. However, quantitative evaluation of design-manufacturing integration is rather limited so far. In this paper, we view design-manufacturing integration as a complex adaptive system (CAS), an effective evaluation method for design-manufacturing integration is proposed. To classify the manufacturing enterprises into which can quickly adapt to the environment or not, support vector machine is utilized. Selecting relevant features among the features available for classification of was also dealt with. The experiment results demonstrate the proposed method is useful for Design-manufacturing integration quantitatively.
Application of Ug Re-Development Technology in 3-D Parameterized Modeling of Injection Mould Parts
Authors: Xiang Long , Sun Wen Lei , He Lian Ying , Zhang Jian , Guo Shu Jun
Published: August 2012

On the foundation of deeply studying UG re-development technology and synthetically utilizing its secondary development tools, including UG/Open MenuScript, UG/Open UIStyler, UG/Open API and Visual C++ 6.0, a dedicated 3D parts library of injection mold is established, parameterized design of injection mold is achieved and mold design efficiency improved.
Quality and Control of Grinding-Hardening in Workpieces
Authors: Liu Ju Dong , Yuan Wei , Xiong Jin Kui , Huang Song Wei
Published: August 2012

On the basis of the surface grinding-hardening test, studied on the quality of grinding-hardening in 65Mn steel. The results show that grinding method has insignificant effect on the microstructure and the high hardness value of the completely hardened region at different locations alone the direction of length. The completely hardened region is composed of fine acicular martensites, residual austenites and a little carbides, and the high hardness value is between 760-820HV. As the changing of grinding method, the uniformity and depth of the hardened layer changed accordingly. The quality of grinding-hardening could be improved with big depth of cut, small table speed and combined with the grinding method of up-down grinding or down-up-down grinding which could effectively control the depth and uniformity of the hardened workpieces.
The Study on Comparison of the Virtual Prototype Modeling Methods Based on Adams/View
Authors: Zhang Li Zhen , Shen Xiao Qing , Cao Shou Qi
Published: August 2012

Virtual prototyping technology is widely used in various industries. Adams/View software is a classic and widely applied simulation and optimization software. In Adams/View, there are two kinds of virtual prototype modeling methods. One is importing a geometry model established in CAD software. The other is direct modeling geometry model by tools for creating in Adams/View. This article compares the advantages and disadvantages of the two methods. Using the second method can build a parametric virtual prototype, and it is easy to modify dimension of prototype, rapidly test different design and do a parametric analysis and optimization design. The common method of parameterize model is point-driven. And the author has put forward a new method of parameterize model called as dimension-driven. In this paper the detailed introduction of modeling ideas and the key technology for both is given. And an example is used to compare two methods for disadvantage and advantage.
3D Surface Reconstruction from Single 2D Image
Authors: Wu Feng He , Wang Jin Fen , Wang Jun , Ren Yu Bo
Published: August 2012

The image-based 3D reconstruction technique is an important method of 3D data passive acquired in computer vision. Aimed at the limitation of traditional SFS based 3D surface reconstruction method, a combined image-based 3D surface reconstruction method is given in this paper. Firstly, the pretreatment method of gradation is applied to convert the input color image to 256 gray image; secondly, shape from shading method is applied to recover the 3D profile of object; finally, the B-spline technique is adopted to reconstruct the model of surface and improve the resolution of surface. The key techniques such as the principle and algorithm of B-spline interpolation reconstruction are analyzed, and the experimental results are also given. The single-image based 3D reconstruction method given in this paper will supply a helpful condition for the extensive used of SFS technique.
Stabilization Accuracy Measurement and Controller On-Line Debugging of Optical-Electro Stabilization System
Authors: Hei Mo , Zhou Qing Kun , Lu Ya Fei , Fan Da Peng
Published: August 2012

In order to reduce the effect of carrier disturbance on the stability of line of sight (LOS) of the optical-electro stabilization system (OESS), a stabilization accuracy model of stabilization loop is built, and the main factors affecting the stabilization accuracy of stabilization loop in OESS are analyzed. Based on the on-line semi-physical simulation theory, a dSPACE measurement system of the LOS stabilization accuracy is designed to measure the LOS stabilization accuracy of the OESS, and the controller of stabilization loop is designed on the basis of the measurement data on-line conveniently. Experimental results show that the stabilization accuracy of the OESS with this method is 0.24mrad which is met the requirement. The novel method of stabilization accuracy measurement and controller on-line debugging for OESS can achieve higher stabilization accuracy and a greater efficiency over the classic method, and also indicates that this novel method is efficient and should be effective on further stabilization accuracy research of OESS.
An Oil Transportation Network Planning Method Based on Evolution
Authors: Chen Guo Rong , Chen Xiao Bo
Published: August 2012

In order to resolve the problem of difficult planning the layout in oil transportation network, a new planning method based on evolution is put forward out in the paper. Firstly, the economic effect in the growth process of oil transportation network is analyzed, then, the attachment formula comes with the growth of the network; based on it, the growth process of adding nodes and edges is discussed, and the clustering coefficient is arrived to balance the degree of the nodes. Case study shows that the evolution designing method is reasonable.
Experimental Research on Dielectric Elastomer Power Generation
Authors: Luo Han Pin , Qiu Fa Cai , Sun Quan Hui , Cao Jian Bo , E Shi Ju , Chen Jia Jun
Published: August 2012

Dielectric elastomer functional materials are new polymer with excellent performance, particularly suitable for power generation of low frequency and large deformation energy source. Based on the dielectric elastomer film material structure, the power generation principle of dielectric elastomer material was discussed, and the influence on the electrical conversion efficiency from elastomer material elongation and area was analyzed by the experiments. The results show that output charge voltage was directly proportional to the size and elongation of the material. This provides the basis for dielectric elastomer material application in the electricity generation.
Influence of the Notch Rounding Radius on Estimating the Elastic Notch Stress Concentration Factor in a Laser Welded Tee Joint
Authors: Niklas Karol , Kozak Janusz
Published: August 2012

In recent years an increased interest of industry in sandwich-type metal structures can be observed. These structures consist of thin plates of 2.5 mm in thickness separated by stiffeners of different shapes and forms. Welds joining the plates and stiffeners are made on the outer side of the plates using laser welding technique. A locally focused source of heat causes the plate to melt creating a very narrow and elongated joint. As a result, sharp geometric notches are formed on the side of the root of a weld – a place which is inaccessible and cannot be checked. Geometries of individual welded joints vary, sometimes considerably, and this makes their analysis even more complicated. Additionally, the use of laser welding technique influences the formation of untypical distribution of changes in material properties in weld zones. The effect is a joint whose behaviour under load is significantly different from the behaviour of a welded tee joint made with the use of classical methods. Fatigue strength calculations for this type of joints can be conducted based on local stress values in notches, which can be determined with the use of Finite Element Method (FEM). This article analyses the influence of the notch rounding radius on the elastic notch stress concentration factor Kt The aim of the analysis is to evaluate the notch stress concentration according to local notch stress approach.
Identification of Efficient Material S-N Curve for Steel Welded Joints
Authors: Blacha Łukasz , Karolczuk Aleksander
Published: August 2012

The paper presents results of simulation and experimental tests carried out in order to identify the S-N curve introduced for the evaluation of fatigue life for various types of steel welded joints. Such curve is explicitly defined through the corresponding values of Cf and mf parameters. The identification process involved finite element analysis, undertaken for different discrete models varying in notch radius. The obtained results served as an input into iterative calculations carried for different values of Cf and mf parameters. Such calculations were aimed at minimization of the estimator in the form proposed for the process of identification.
The Impact of the Laser Welding Speed on the Mechanical Properties of Joints in Multilayer Pipes
Authors: Mroziński Stanisław , Piotrowski Michał
Published: August 2012

The paper assessed the impact of the laser welding speed on the strength and fatigue properties of the aluminum layer found in multilayer pipes. The conducted experiment has shown that during the adjustment of the welding speed one has to take into account not only the results of static tests, but also the results of fatigue tests. The impact of the welding speed on fatigue life depends on the level of stress max. This level is slight in the area of the biggest stresses and increases along with the decrease in stresses.
Model of the Deformation Process under Thermo-Mechanical Fatigue Conditions
Authors: Okrajni Jerzy , Junak Grzegorz
Published: August 2012

The paper focuses on the development of a mathematical representation of deformation characteristics under the conditions of an elevated changeable temperature and mechanical loads. The method proposed in the paper is based on the use of characteristics determined in low-cycle fatigue tests at constant temperatures. Hysteresis loops reflecting the behaviour of a material under the conditions of low-cycle loads at an elevated temperature were primarily used. The effect of relaxation on the course of the hysteresis loop was taken into account. The steady state of the material is referred to in the proposed representation. A calculation algorithm was developed to enable the determination of the stress value for subsequent increases of strain over time. The results obtained were compared with experimentally determined characteristics.
Fatigue Life Calculation in Conditions of Wide Spectrum Random Loadings – The Experimental Verification of a Calculation Algorithm on the Example of 41Cr4 Steel
Authors: Ligaj Bogdan , Szala Grzegorz
Published: August 2012

Precision of fatigue life calculations of structural elements in programmed loading conditions is connected with proper elaboration of loading spectrum and assumption of a proper fatigue characteristic. On the base of literature data and own research there has been elaborated an algorithm for fatigue life calculations in random loading conditions with wide spectrum. Calculations were performed with the usage of chosen mathematical models of two-parametric fatigue characteristics. Results calculated with accordance to the described procedure were validated with experimental test results of specimens made of 41Cr4 steel with a method of programmed fatigue life tests.
Steel X2CrNiMo17-12-2 Testing for Uniaxial, Proportional and Non-Proportional Loads as Delivered and in the Annealed Condition
Authors: Skibicki Dariusz , Sempruch Janusz , Pejkowski Łukasz
Published: August 2012

The article presents the results of fatigue life and fractographic testing of steel X2CrNiMo17-12-2 exposed to proportional and non-proportional fatigue loads. The following load types were applied: tension-compressive strength, torsion, proportional combined/complex loads produced by tension-compressive strength and torsion as well as non-proportional combined load – by tension-compressive strength and torsion by the phase shift angle φ=90°. The paper analyses the effect of the load method on the fatigue life and fractography of fatigue fractures recorded, and especially the effect of non-proportional load.
Fracture Toughness of Structural Members
Authors: Neimitz Andrzej
Published: August 2012

Abstract. In the paper several formulae to compute the fracture toughness are presented. The formulae include either parameter characterizing the in-plane constraint or out-of-plane constraint or both. The formulae are based on different assumptions and approaches to fracture mechanics. Namely, small or finite strains were assumed, global or local approach was adopted. In all cases the standard, plain strain fracture toughness was used as a reference state.
Fatigue Crack Growth Rates of S235 and S355 Steels after Friction Stir Processing
Authors: Kocańda Dorota , Hutsaylyuk Volodymyr , Ślęzak Tomasz , Torzewski Janusz , Nykyforchyn Hryhoriy , Kyryliv Volodymyr
Published: August 2012

Abstract. In the study, there were investigated the effects of friction stir processing (FSP) which was applied in order to improve the surfaces of notched specimens made of S235JR and S355J2 carbon steels, on their fatigue crack growth rates in the air. There were presented the results of comparative fatigue tests conducted at asymmetric tension (R= -0.2) for these steels treated by means of FSP and for the ones in the delivery state. The method of successive etched material layers used revealed the presence of internal tensile stresses in the surface layers of treated specimens. Crack growth rates were described on the basis of non-linear fracture mechanics, taking the effects of internal stresses into account.
Application of Digital Image Correlation in Fatigue Crack Analysis
Authors: Marciniak Tomasz , Lutowski Zbigniew , Bujnowski Sławomir , Boroński Dariusz , Giesko Tomasz
Published: August 2012

In the paper method of displacement analysis in the cracking zone based on digital image correlation and advanced multi-processor graphic cards procedures was presented. The basic assumption for the discussed displacement and strain measurement method under time variable loads was obtaining high measurement sensitivity by simultaneously minimizing the measurement time consumption. The developed digital procedures for correlation of images has been used for an example of displacement analysis in the crack propagation testing in airplane riveted joints.
The Fictitious Radius as a Tool for Fatigue Life Estimation of Notched Elements
Authors: Robak Grzegorz , Szymaniec Marcel , Łagoda Tadeusz
Published: August 2012

In this paper, the fictitious radius - according to Neuber’s method for determination of stresses at the notch root was used. Next, the fatigue lives of elements of the ring notches were calculated, and then compared with results of experimental tests of S235JR steel samples. However, the obtained fatigue lives did not bring satisfactory results. It has been demonstrated that the fictitious radius strongly depends on the expected fatigue life
Low Cycle Fatigue Life of Martensitic Cast Steel after Ageing
Authors: Golański Grzegorz , Mroziński Stanisław , Werner Krzysztof
Published: August 2012

The paper presents the results of research on fatigue life of GX12CrMoVNbN9 – 1 (GP91) cast steel in the as-received state and after ageing at the temperature of 600 °C. The fatigue of low cycle scope was performed at the temperature of 600 oC at the strain amplitude level of εac= 0.25 ÷ 0.60%. Analysis of the tests carried out has shown that the examined cast steel is characterized by strong cyclic softening without an evident period of stabilization. Ageing of GP91 cast steel leads to the fatigue life reduction by ca. 7 to ca. 35%, depending on the level of strain amplitude εacin comparison with the as-received condition.
Concept of Fatigue for Determining Characteristics of Materials with Strengthening
Authors: Marcisz Ewa , Niesłony Adam , Łagoda Tadeusz
Published: August 2012

The paper presents the concept of division of the total strain amplitudes. Simulations were performed for high-alloy steel X6NiCr3220 for proposing a new curve of cyclic strain based on the best fit to the experimental points and plotted the hysteresis loop. Proposed allocation of the total strain amplitude in three parts: the plastic strain amplitude, strain amplitude and the amplitude of the linearly elastic strain coupled. In order to preserve the forms of popular formula Ramberg-Osgoda and Manson-Coffin-Basquin modified them in such a way that added to their member responsible for the description of the coupled strain. Inclusion of additional term leading to closer representation of the actual material properties.
Material Properties Investigations With the Use of Microspecimen
Authors: Boroński Dariusz
Published: August 2012

In the paper there are discussed possibilities of performing static and cyclic investigations of a material properties with the use of small size specimens. An original research system developed at the University of Technology and Life Sciences in Bydgoszcz has been used for static and fatigue testing. Thanks to tests performed on microspecimens it is possible, among others, to determine the material local properties in objects with the material discontinuities. This research provides exemplary results of fatigue tests carried out on microspecimens taken from a laser welded joint.
Effect of Microstructure on Rolling Contact Fatigue of Bearings
Authors: Woźniak Tadeusz Z. , Jelenkowski Jerzy , Rozniatowski Krzysztof , Ranachowski Zbigniew
Published: August 2012

There has been proposed an innovative thermal treatment of bearing steel 100CrMnSi6-4, where the existing standard heat treatment has been replaced by austempering. The structure of low-temperature tempered martensite has been replaced by a microstructure composed of martensite and lower bainite with midrib. The kinetics of bainitic transformation and isothermal martensitic transition at selected austempering temperatures was controlled by acoustic emission. The research on contact strength was made under the conditions of rolling-sliding friction. The microstructure was revealed with the use of a light microscope and the forms of pitting wear were displayed by a scanning electron microscope. It was found that the optimum microstructure providing the best used contact strength of the tested steel is conditioned by the formation of a lower bainite with midrib at the temperatures near MS. A plausible cause of the increased resistance to pitting is bifurcation of fatigue cracks on dispersion bainitic carbides in combination with primary carbides, in bainitic-martensitic matrix.
Determination of the Fatigue Properties of Aluminum Alloy Using Mini Specimen
Authors: Tomaszewski Tomasz , Sempruch Janusz
Published: August 2012

There are situations where taking normative specimens is impossible due to the dimensions of the objects investigated (e.g. extruded sections) and one of the solutions is to use mini specimens. As for non-standard specimen testing, it is essential to define the effect of size on fatigue strength. The research methodology facilitates the determination of fatigue characteristics (S-N) for EN AW-6063 aluminum alloy. The material is used to manufacture the extruded section in the process of extrusion of the material through the extruding die. The methodology assumes the geometry of the mini specimen and the normative specimen. As for the material strength identification, a static tensile test for the specimens made directly from finished elements and preliminarily strained in cycles was carried out. As a result of the cyclic material reinforcement, an increase in yield strength Re was observed, which, in turn, rejects Re as the upper criterion of the high-cycle fatigue range. The essential fatigue tests were performed based on unilateral cyclic tension (R = 0.1). The effect of size on fatigue strength was defined. Theoretically aluminum alloy non-sensitive to changes in the size of the cross-section showed a different strength in mini and normative specimens.
Microstructure of Ceramics TiO2 Obtained by Protein Consolidation
Authors: Santana Jerusa Góes Aragão , de Campos Élson , Ferreira de Lucena Emerson , Mota Rogério Pinto
Published: August 2012

Porous ceramics can be produced by adding starch (corn, potato) and protein (animal or vegetable) to raw material as pore forming element. In this study, titanium dioxide ceramics were formed by vegetable protein consolidation. Soybean was chosen as the binding agent and pore forming. The samples, which were produced in cylindrical shape, had the following processing: material mixture, gelling, drying, pre-sintering and sintering. Heated platinum microscopy were performed by using suspensions with different compositions in order to verify protein gelling capacity and better know the temperature in which this process occurs. The samples were characterized by apparent porosity and roughness measurement. Besides, imaging by light microscopy was also performed in order to determine the sample morphology and porosity.
Production of Ti-13Nb-13Zr Alloy by PM for Biomedical Applications Using Zirconium Oxide Grinding Bowl and Balls
Authors: Duvaizem José Hélio , Fajardo A.M. , Barbosa Luzinete Pereira , Bressiani Ana Helena Almeida , Takiishi Hidetoshi
Published: August 2012

In this present work Ti-13Nb-13Zr alloy was produced by PM using planetary ball mill with zirconium oxide grinding bowl and balls to reduce contamination. The effect of milling time upon microstructure and microhardness was studied. Powders have been produced by hydrogenation of Ti, Nb and Zr at 1MPa. Milling speed was 200 rpm during 90 to 360 min. Sintering was carried out at 1150°C during 10h. Powder size distribution was analyzed using CILAS equipment and chemically characterized by X-Ray Fluorescence (XRF). Microhardness was determined by means of a Vickers microhardness tester. Microstructure and phases were analyzed employing scanning electron microscopy (SEM) and X-Ray diffraction.
Sintering of Alumina Powders Obtained by a Pechini-Type Method with Addition of Seeds
Authors: Salem Raphael Euclides Prestes , Guilherme Keterine Alves , Chinelatto Adriana Scoton Antonio , Chinelatto Adilson Luiz
Published: August 2012

Alumina ceramics are used in many areas of modern industry because of their excellent mechanical, thermal and optical properties. Sintering of alumina usually requires high temperatures (> 1600°C), due to the large and extensive pore network developed during the reconstructive transformation to its stable alpha phase. Consequently, it is very difficult to suppress grain growth during sintering. In this work it was studied the sintering behavior of alumina powders obtained through a modified Pechini-type method, with addition of seeds of calcined alpha-alumina. Powders without addition of seeds were synthesized for comparison. After calcinations at the temperature of 1000°C, the powders were uniaxially pressed. The compacts were sintered in air in the range of 1400-1600°C and characterized by density and porosity measurements, scanning electron microscopy, X-ray diffraction and infrared spectroscopy. The behavior in the sintering of the compacts with addition of seeds was clearly different compared with the compacts with no seeds.
Influence of the Granite Waste into a Clayey Ceramic Body for Rustic Wall Tiles
Authors: Gadioli Monica Castoldi Borlini , de Aguiar Mariane Costalonga , de Andrade Pazeto Abiliane , Monteiro Sérgio Neves , Vieira Carlos Maurício Fontes
Published: August 2012

This work has as its objective to evaluate the influence of a granite waste into a clayey ceramic body for obtaining of rustic wall tiles. As raw materials, a clayey ceramic body for red ceramic production and a granite waste, resulting from ornamental stones cutting with the multi-wire technology were used. Compositions using 0, 10, 20 and 30% of waste incorporated into ceramic body were prepared. Specimens were fabricated by uniaxial press-molding at 20 MPa and sintered at 1050°C. The following properties were determined: linear shrinkage, water absorption and flexural rupture strength. In general, within the error bar, there was no influence of the waste in the values of water absorption of the clayey ceramic body. The results showed that all investigated formulations used in this work for the production of rustic wall tiles attend the standards for water absorption and mechanical strength.