bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Kinetic Competitions of Crystal Growth
Authors: He Tao
Published: May 2013

One of the key issues is in crystal growth technologies is control of crystal morphology. This paper attends to understand film growth in its full generality is to propose a growth law, and it is capable of describing all types of growth mechanisms and determining the growth morphology at different stages of growth. We refer to an axiomatic approach to identify the important scaling in growth processes. One way to determine which processes dominate the competition is to form dimensionless parameters which embody the competitions between pairs of kinetic processes.
Applications of a New Element Model of Solid Bodies in Plasticity
Authors: Ke Jiang
Published: May 2013

Based on the deformations under the equivalent external forces are the same, a new element model of elastic perfectly-plastic and orthotropic solid bodies is presented, and the elastic perfectly-plastic and isotropic materials is a special subclass. Furthermore, the method for determining the displacements, the stresses and the strains of a body under the action of applied forces has been given. A new method for predicting the engineering elastic constants of a fiber-reinforced composite material is also presented. It can be found that the precision by using the new element method is good, and the limit analysis has the highest precision in all methods.
Analysis of Fatigue Life and Influence Factors of Tubing with Initial Crack
Authors: Cao Yin Ping , Dou Yi Hua
Published: May 2013

Three-dimensional stresses are analyzed in the tubing working based on the theory of thick-walled cylinder, and the stress intensity factor expression is derived on longitudinal and circumferential extending cracks in the tubing. Tubing fatigue life is calculated according to given condition through the preparation of the corresponding program. Influence of initial crack length, change of the pressure and the tubing wall thickness on the fatigue life are discussed.
Investigation and Analysis on Transverse Crack Spacing Distribution in Continuously Reinforced Concrete Pavement in China
Authors: Zhao Quan Man , Zhang Hong Liang , Wang Yan Hui
Published: May 2013

The longterm field investigations in the US showed that punchouts were the most important distress in continuously reinforced concrete pavement (CRCP) and often developed in the cluster cracking with the crack spacing of 0.3m-0.6m. But, it was not sure whether punchouts were the most important distress in CRCP in China, so this paper carried out field investigations on several CRC pavements in China. Results showed that punchouts were the most serious distress and often occurred in cluster crack regions. Furthermore, this paper analyzed the transverse crack spacing distribution. Results showed that the transverse cracks spacing distribution followed Weibull’s distribution.
Research of Baseball’s Best Batting Position Changes with the Selection of Material of Baseball
Authors: Du Li Ping , Li Wu , Han Wen Sheng
Published: May 2013

From the aspect of the fastest exit speed of the ball and through the collision model of mechanics, we analyzed the best hitting point which results in the fastest exit speed of the ball and the change of the best hitting point. Based on this model, we gave a very practical definition of the sweet spot, and we also found out the effect of the baseball bat’s material on the sweet spot. The distances from the best hitting point to the end of the baseball bat result from the three different materials, which are the bat’s original material, aluminum and the corked material. Through the sensitivity analysis, three parameters affecting the hitting position resulting in the ball’s fastest exit speed are the weight of the bat, the center of mass and the moment-of-inertia. In the process of the three parameters’ calculation, the infinitesimal method is used. As can be found out that the length of the sweet spot results from the corked and the aluminum are much longer than results from the original material. The longer the length of sweet spot, the possibility that the hitter hits the fast ball is higher. Also ball hit by the aluminum bat is faster than that hit by the bat made out of the original material. The above analysis can explain that why the aluminum bat and corked bat are prohibited by Major League Baseball
Development of Hard Rock Cutting Tool with Advanced Diamond Composites
Authors: Li X.S. , Sun Yong
Published: May 2013

The modern mechanical excavation machines have enough power for cutting hard rock. The bottle neck which limits the use of machines for hard rock excavation is cutting tool. To cut hard and abrasive rock, CSIRO has been developing Super Material Abrasive Resistant Tools (SMART*CUT). SMART*CUT technology replaces the tungsten carbide (WC) tip of conventional pick with thermally stable diamond composite (TSDC) and attaches the TSDC tip to steel tool body with CSIRO worldwide patented bonding technology. This paper compares its performance with conventional WC tipped tools by a series of hard rock cutting tests. The cutting and normal forces acting on the tools were measured during these tests. The tests shown that the cutting performance of SMART*CUT pick was significantly better than that of WC pick. The testing results indicate that TSDC can be applied as an effective cutting tool material for cutting hard and abrasive rocks.
Research on Properties of Materials Based on Extension Evaluation Method
Authors: Liu Yao Lin
Published: May 2013

The matter-element model of mechanical properties of materials for grade-evaluating is established based on the matter-element theory and extension evaluation theory in the Extencis. Then the dependent function derived from extension set is used to calculate integrated correlation degree, after the Weight of each evaluation index is determined, then the grade of corresponding material will be obtained. take the metal materials for example, the results have proved that this kind of extension evaluation method applied is sure to be more scientific、normative, fair, and reasonable, which deserves to be populated and generalized.
Influence of Rear Earth Yb on the Specific Heat of Liquid Fe-Co-Yb Alloy
Authors: Yao Wen Jing , Wang Nan , Lee Jeh Yun
Published: May 2013

By Monte Carlo method with EAM potentials, the specific heat of liquid Co50Fe50and Co48Fe48Th4alloys at different temperatures are obtained. The effect of Th on the thermophysical parameters is examined. Over the temperature range from 1400 to 2000 K, the specific heat decreases from to Jmol-1K-1after Th was added. It is the addition of Th element which has bigger atomic radius, larger atomic mass, and complex arrangement of extranuclear electron, leads to the reduced specific heat.
On the Experimental Investigation of Rock Abrasiveness in Petroleum Engineering
Authors: Wei Zhen , Wang Zong Gang , Zhao Xiu Ju , Feng Guang Tong
Published: May 2013

By means of developing new rock abrasiveness device and using quenching steel spiral simulation micro-bit, the experimental investigation on rock abrasiveness that simulating the actual drilling surroundings in petroleum engineering had been conducted. based on the data of micro-bit’s wear weight, which broke unit volume rock, of which experimental samples are made from more than 850 cores of seven main geological profiles in Shengli oilfield, rock abrasiveness is divided into eight grades with Sturges empirical formula. The bit type selection and the bit life prediction could be conducted with the upper experimental method.
Characteristics of Thin Metal Plate Being Strengthened by Laser Irradiation
Authors: Choi Seong Dae , Kim Gi Man , Yun Seong Ho
Published: May 2013

The general method for strengthening the surface hardness is known to be heat treatment by means of the laser. Generally, the smaller and the lighter component is hopefully used for parts of machine or complicate structure. Hence, Instead of a heavy structure, a thin panel with sub structure or engraving the grooves or waving on that is used. It is noted well that those processes make an original structure strengthened. Therefore it is expected that the thin plate panel can be much more strengthened and stable through processing of the metal surface by laser beam irradiation. Through this research, it would be explained empirically how the hardness be changed and mechanical characteristic changed by width and depth of groove by laser affect. As of conclusions, the structural characteristics of a thin plate being strengthened locally by laser irradiation will be presented in comparison with the results obtained from FEA analysis
Finite Element Analysis of the Strength of Ladder Type Structure of the Deep-Water AUV
Authors: Wei Dong Jie , Zhang Lian Hong , Zhang Hong Wei , Liu Fei
Published: May 2013

Autonomous underwater vehicle (AUV) is one of the current research hotspots in the field of robotics. It has abroad application prospect in the oceanographic survey, resource exploration and military fields. The AUV presented in this paper is mainly used for investigating the deep water oil and gas resources and works in underwater 3000 meters. It carries a series of measuring equipment, such as battery, sensors and pressure-resistant cabins, to engage in exploration tasks. When the AUV is lifted in water or in air, the loads acted on the main frame of AUV are different. In order to realize lightweight design and save buoyancy within the allowable range of the material strength, this paper puts forward a novel ladder type construction with two longitudinal beams and five crossbeams made of stainless steel, and analyzes the forces sustained by the main frame when lifted. Compared with traditional aluminum welding structure frames, the advantages of the trapezoid frame of the deep water AUV are as follows: large effective capacity, strong bearing capability and convenient maintenance. At the same time, using GRP hulls can improve the total structural strength significantly. The validity of the design and analyze is verified by recent at-sea trails.
Theoretical and Numerical Solution of Deflection of the Circular Ring under a Concentrated Force
Authors: Wang Xiao Zeng
Published: May 2013

A circular ring is often used in the engineering. There are many applications in the tunnels, subways, and down hole. The purpose of this paper is to obtain the theoretical and numerical solution of the deflection of the circular ring under action of a concentrated force. Adopting the method of numerical analysis and Castigliano’s theory, the max deflection and the 4th equivalent stress of ring are developed. The results of the research indicate that the deflection of ring is the linear function of the concentrated force which is in accord with the elasticity body assumptions, that is Hook’s law. The theoretical solution of the deflection of ring is almost the same as the numerical one of the ring. So it is feasible that the numerical model of the ring is used to analyze the deflection of the eccentric ring.
Thermodynamic Analysis and Observation of Inclusions in H13 Die Steel with Rare Earth
Authors: Liu Xiao , Liang Jing Long
Published: May 2013

The effect of RE on modifying inclusions of H13 die steel was studied by metallographic examination, SEM and electron spectroscopy. Thermodynamic calculation was used to analyze the formation of RE inclusions in H13 die steel. The result shows that sulfide inclusions are modified to round RE complex inclusions after adding RE to H13 die steel.
Research on Screw Pump Rotor Eccentricitys Influence on Sucker Rod Partial Abrasion through Contact Analysis
Authors: Zhu Juan , Zou Long Qing , Yuan Xiao Jing , Zhang Lu Wei
Published: May 2013

Through the establishment of contact element simulated the contact between sucker rod and oil pipe. The deformation of sucker rods in oil pipe that caused by the screw pump rotor eccentricity has been researched by the application of transient dynamics analysis. Results show that screw pump rotor eccentricity is one of the reasons which cause rod and oil pipe contact resulting in partial abrasion. Deformation of the sucker rods caused by the rotor eccentricity is mainly concentrated on the bottom of rods, so in order to mitigate partial abrasion, rod centralizer arrangement at the bottom of rods should be strengthened, or change the connection mode between the sucker rod and screw pump rotor to eliminate the effect of the sucker rod deformation caused by rotor eccentric motion.
Acoustic Emission Signals Characteristics of Q345R at Tensile Progress in the Normal and Low Temperatures
Authors: Long Fei Fei , Wang Qiong , Song Yang , Li Wei
Published: May 2013

Acoustic emission signals were collected during the tensile process of Q345R at the normal and low temperatures. The signals were analyzed by the single parameter analysis, distribution analysis and correlation analysis to result the acoustic emission characteristics of Q345R in the normal and low temperatures.
Fever Analysis and Engineering Applications of the Heavy Machine Tool's Main Bearing
Authors: Chen Shui Sheng , Li Shuang Qiang , Hua Zhong Ping , Dai Chen
Published: May 2013

Large heavy-duty CNC machine tools commonly used rolling bearing as Main bearing. This paper analyses the causes of Main bearing fever deeply, pointing out the mechanism of the bearing heating; combined with the practical application of the TK6926 landing CNC milling and borings main bearing, putting forward the main method to reduce the rolling bearing fever and achieved good results.
Progress on Facilities and Methodology to Evaluate Abradable Seal Coatings
Authors: Lu Qiu Yuan , Shen Jie , Yu Yue Guang , Ren Xian Jing , Xuan Hai Jun , Liu Tong
Published: May 2013

To improve gas turbine performance, it is essential to decrease back flow gases in the high-temperature combustion region of the turbo machine by reducing the shroud/rotor gap. An abradable seal coating will function effectively. The present work described an advanced detection technology and test rigs to study abradability of the seal coatings. Several early used analytical methods were also reviewed in the work as comparison,like NASAPWA and Sulzer Innotec, have developed abradable test rigs and specified different experimental parameters by simulating the determined working conditions. Thence, suggestions to further develop evaluation methods for seal coatings were proposed and discussed.
Study on Tribological Performances for Textured Bearing of ICE
Authors: Meng Fan Ming , Yang Tao , Long Tao
Published: May 2013

The influence of dimples on the inner surface of big end bearing in internal combustion engine (ICE) on tribological performances of the bearing was investigated based on Navier-Strokes equation and other associated equations. In doing so, the CFD modulus in the software ANSYS12 version is used to analyze the dimple effect on the tribological performances of the bearing using two-way fluid-solid coupling algorithm. Some mechanisms are revealed about the dimple effect on the load-carrying capacity and friction coefficient of oil film, and the deformation and stress for the textured big end bearing.
Study Film Temperature Including Cavitation Effect of Sliding Bearing by CFD Method
Authors: Meng Fan Ming , Long Tao
Published: May 2013

The film temperature of sliding bearing considering the cavitation is studied based on the Rayleigh-Plesset (PRE) model with the computational fluid dynamics (CFD) method. The numerical results show that the maximum film temperature with the cavitation effect becomes smaller than that without the cavitation effect. The larger average vaporization rate of the film, the more decrease in the film temperature.
Experimental Investigation on Ultrasonic Vibration Assisted Turning of Stainless Steels with PCD Tool
Authors: Dong Guo Jun , Zou Lai , Zhou Ming
Published: May 2013

The demand for surface quality and dimensional accuracy of ferrous metallic components has increased markedly at present. Whereas, it is clear known that diamond tool could not be used for cutting operation of ferrous metals ascribed to excessive tool wear. In this paper, a series of experimental investigations for various stainless steels with ultrasonic vibration assisted turning were proposed. The micro-morphology of rake and flank face of diamond was detected by scanning electron microscopy, in order to discuss the influence law of material composition on tool wear. In addition, the effect of cutting parameters such as depth of cut, feed rate and amplitude on tool wear and surface quality were deeply studied with ultrasonic vibration cutting. The results revealed that this technological measure has enhanced tool life, decreased cutting force and improved surface quality to a large extent.
Study of the Effect of Tool Wear on Cutting Ti6Al4V Process
Authors: Yang Shu Bao , Ni Hong Chao , Zhu Guo Hui
Published: May 2013

Ti6Al4V alloy is widely used in the aircraft industry, marine and the commercial applications due to its excellent comprehensive properties. However, its poor machinability prevents it from application widely, and the rapid tool wear is one of the key factors. The FEM models of cutting titanium alloy are established. The effect of tool wear on chip morphology, cutting temperature and cutting force are studied. The simulation results show that: the cutting force and cutting temperature will rise with the increase of tool wear. Furthermore, the degree of chip deformation will improve, but the frequency of serrated chip tooth occurred will decrease.
The Irradiation Effects of Metal Gold Surface by Intense Pulsed Ion Beam
Authors: Wu Di , Du Yong Jian
Published: May 2013

We report a modification method for Gold target by intense pulsed ion beam (IPIB) irradiation. Based on the temporal and spatial distribution models of the ion beam density detected by Faraday cup in the chamber and the ions accelerating voltage, the energy deposition of the beam ions in Au is calculated by Monte Carlo method. Taking this time-dependent nonlinear deposited energy as the source term of two-dimensional thermal conduction equation, we obtain the temporal and spatial ablation process of metal Au during a pulse time. The top-layer Gold material in thickness of about 0.25μm is ablated by vaporization and the layer in thickness of 1.40μm is melted after one shot at the ion beam density of 300 A/cm2.
The Study of Aromatization Performance of HZSM-5 Catalyst Deposited Silicon on the Surface
Authors: Zhu Jing , Ban Yu Feng , Sun Ming Zhu , Zhang Bing , Wang Hai Yan
Published: May 2013

FCC gasoline fraction (75~120°C) is feedstock, Ethyl silicate (TEOS) or γ-aminopropyl triethoxysilane were used as the silicon source respectively, aromatization were examined on the fixed-bed reactor. The catalyst activity and stability are improved when SiO2 depositions are 2% and 10%, respectively.
Characteristics Evaluation of Coating Film by Thermal Spray in Seawater Solution
Authors: Moon Kyung Man , Nam Mun Jin , Lee Yeon Chang , Kim Yun Hae , Jeong Jae Hyun
Published: May 2013

Many surface protection methods have been developed to apply to constructional steels to be used under severe corrosive environments. Thermal spray coating has been known to be an attractive technique due to its relatively high coating speed. However, the high corrosion resistance of coating films deposited by thermal spray method is increasingly required to expand its application. Four types of coated films (DFT: 200um), that is, pure zinc, pure aluminum, and two Al-Zn alloy (Al:Zn=85:15 and Al:Zn=95:5), were coated onto carbon steel (SS401) with arc spraying, and the corrosion behavior of their samples were evaluated by the electrochemical method in this study. The pure aluminum sample had the best corrosion resistance when exposed to seawater solution and alloy (Al:Zn=85:15), so called galvalume and alloy (Al:Zn=95:5) samples followed the pure aluminum sample. The pure zinc sample ranked 4thin corrosion resistance in this study. Morphology of corroded surfaces of pure aluminum and alloy (Al:Zn=85:15) samples exhibited a general corrosion pattern, however, the patterns of intergranular and pitting corrosion were observed for the pure zinc and alloy (Al:Zn=95:5) samples respectively. Pure zinc sample had the smallest value of porosity ratio compared to other samples due to its heavier density. Keywords : Surface protection methods, Thermal spray, Corrosion resistance, Pure aluminum, Pure zinc, Porosity ratio
Effect of Loading Rate on Tensile Properties of Automotive Steel Sheet
Authors: Qin Jin Gui , Lu Fang Yun , Lin Yu Liang , Wen Xue Jun
Published: May 2013

Results of uni-axial tensile loading of three automotive steels at different strain rates (0.0011–3200s-1) are reported here. Quasi-static tensile tests were performed under the strain rate of 1.1×10-3 s-1 using an electromechanical universal testing machine, whereas dynamic tests were carried out under the strain rate in the range of 1100 to 3200 s-1 using a Split Hopkinson Tensile Bar apparatus. Based on the experimental results, the material parameters of widely used Johnson–Cook model which described the strain rate and temperature-dependent of mechanical behaviour were determined. The experiments show that strain-rate hardening is superior to thermal softening: yield stresses, tensile strength, deformation, and energy dissipation increase with the strain rate from quasi-static tests to dynamic tests. The Johnson–Cook model can describe the behaviour of these steels and provides the opportunity to study the material and structural response.
Effect of Electro-Spark Deposition Process Parameter on WC Coating Thickness of H13 Steel Surface
Authors: Wang Ming Wei , Pan Ren , Xin Wen , Chen Wen Qiang , Zhao Xiu Jun , Li Shu
Published: May 2013

A simple and effective surface coating technique, electro spark deposition (ESD), has been used to produce WC coatings onto H13 steel surface. Influence of process parameter (output voltage, output capacitance, discharge frequency, specific deposition time at el) on the coating thickness was studied. It can be seen, choose output voltage 80V, output capacitance180 μF, discharge frequency 2000 Hz, specific deposition time 8min/cm2 obtained to optimal overall quality of coating. The morphology and microstructure of coatings were analyzed using scanning electron microscopy (SEM). The WC coating had an average thickness of about 60 μm and formed metallurgical bonding with the substrate.
Study on the Surface Plasma Hardening Treatment and Anti-Penetration Mechanism of Armor Steel
Authors: Yu Kai Ping , Wang Feng , Chen Rong Gang , Zong Jun Jun
Published: May 2013

Plasma surface hardening process was performed to improve the surface on the 22SiMn2TiB steel by plasma transferred arc. Experiments were carried out to characterize the hardening qualities. The anti-penetration ability and mechanism were analyzed, and hardness protective layer can improve greatly the ability of armor protection. The dual hardness armor steel composed of high hardness panel and basic backplane was developed based on the experimental results.
The Study on Preparation and Apply of Ni-Co-P Alloy Coating
Authors: Li Nai Jun , Li Mei Mei , Li Nai Wei
Published: May 2013

The study on combinatorial additives and plating technics for preparation and apply Ni-Co-P alloy coating was carried out completely, and the Ni-Co-P alloy with functional, corrosion-resistance and ornamental multicomponents was found, the optimum technics of plating multicomponents alloy was been found. The coating made in optimum technics was good in corrosion-resistance and wear-resistance, and with a smooth, fine, shining surface. It was proved by determinations that the 8.2% phosphorus in the coating and the coating was amorphous crystal. It was found that the combination force between the substrate and coating was very good, the corrosion-resistance and abrasion-resistance of coating were much better than that of Ni-P alloy according to the examination, the Ni-Co-P alloy coating with special character which were good magnetic properties and finery in ornamentally also.
Phase Evolution and Mechanical Properties of Cr-C Coatings Deposited by Reactive Unbalanced Magnetron Sputtering Process
Authors: Yang Yu Sen , Huang Wen Yi
Published: May 2013

Cr-C coatings with gradient Cr/CrN/CrCN inter-layers were studied to elucidate the effects of carbon contained on the mechanical properties and microstructures of the deposited coatings. The coatings were deposited by using a reactive sputtering system with constant total flow rate, target current and substrate bias. Percentage of C2H2flow rates were varied from 10 % to 50 %. Carbon contains in the film were measure by EDS. Mechanical properties of the coatings were evaluated with micro-indentation, scratch tester, ball-on-disk tribo-tester. Microstructures of the films were characterized by SEM, TEM, and X-ray diffractermeter. The experimental results show that carbon contain increase from 21.6 %to 99.5 % with respect to C2H2flow rates varied from 10 %, 20 %, 30 %, 40 %, 50%. And the phase of coatings change from Cr solid solution to Cr+Cr23C6+ amorphous diamond like carbon (DLC) and then to DLC +Cr7C3and then to DLC+ Cr3C2+Cr7C3. The hardness of the coatings increase with C2H2flow rate increased and achieved the maximum value of Hv1815 at 50% C2H2flow rate. The coefficient of friction decreases from 0.630 to 0.285 when C2H2flow rate increased from 10% to 50%. The wear rate decreased with increasing the C2H2flow rate.
First-Principles Study on Elastic Properties and Electronic Structure of Ti1-xAlxN
Authors: Tan Xin , Xin Zhen Yang , Liu Xue Jie , Zhang Qing Bin , Jia Yichao
Published: May 2013

As excellent performance coating material, the TiAlN coating has become alternative to TiN coating, with a very broad application prospects. We calculated the lattice constants, elastic parameters, electronic constants of Ti1-xAlxN. Its elastic constants trend was downward as the Al element contents increasing, and its brittleness fell. We had analysed the band structure and density of states of TiA1N, and TiA1N was illustrated to be conductor.
Design of a New Type Flexible Stretch-Forming Machine
Authors: Han Qi Gang , Li Ming Zhe , Zhang Qiang , Chen Ya Dong , Fu Wen Zhi
Published: May 2013

Stretch forming machine (SFM) is most effective plastic forming equipment for large-size, thin and flat-deformation parts, which can decrease the springback phenomenon in sheet metal forming. In order to enhance the performance of SFM, a flexible stretch forming machine (FSFM) was developed by the authors successfully, which is made up of jaw clamping mechanisms, stretching mechanisms, universal push-pull mechanisms, and a carriage. Our experimental results indicated that the rate of materials utilization and close-fitting dies can be increased to 80 %. In addition, FSFM can reduce the complex of control-system and decrease the expense of machine sharply. FSFM have been used for double-curved sheet metal manufacturing successfully, such as the cab of high-speed train. This work has a strong value in enhance the stretch forming technology for double-curved sheet metal parts.
Effect of Tempering Process on Residual Stress in Hot Rolled Low Carbon Martensite High-Strength Steel Strip
Authors: Sun Lin , Zhao Zhi Yi , Yang Xiao Zhen , Xue Run Dong
Published: May 2013

Distribution of residual stress in hot rolled low carbon martensite high-strength steel strip was measured by means of blind-hole method in the steel before and after tempering. The hot rolled low carbon martensite high-strength steel strip was tempered at 450°C, 500°C, 550°C or 600°C. Before tempering, the value of the residual stress along the width direction is maximum at the edge, intermediate at the center, minimum at the 1/4 of the strip. The figure of the residual stress distribution along the width direction is like the shape of the letter M. Residual stress of the strip is reduced after tempering. When tempering at 450°C or 500°C, evolution of residual stress is caused by changes of thermal stress. Distribution of residual stress becomes gentle. With tempering temperature increasing, distribution of residual stress is reversed, because evolution of thermal stress and phase transition stress changes in different time.
Effects of Strip Thickness Difference on Deviation in Aluminum Hot Rolling
Authors: Ma Li Yong , Liu Yi Lun , Zhao Xian Qiong , Liu Chi
Published: May 2013

In aluminum hot rolling process, strip thickness difference plays a more important role in deviation. An FE model was presented to simulate the rolling process in which strip thickness difference was taken as a horizontal asymmetry factor of disturbance. Parameters information of nodes is processed, with the characteristic quantity of deviation and the asymmetrical thickness difference rate calculated. The result of simulation illustrates the deviation result under the disturbance of thickness difference, and the relationship among deviation function, characteristic quantity of deviation and the asymmetrical thickness difference rate. Deviation tracks under these circumstances are figured out. The effect of thickness difference on deviation in aluminum tandem hot rolling is revealed.
Development of Secondary Controlled Hydraulic Pressure Forming of Sheet Metal for Energy Saving and Re-Utilization:
Authors: Celestine N. Okoye , Evans Chukwudi Onwukwe , Urama Richard
Published: May 2013

This paper presents the development of secondary controlled hydraulic pressure forming of sheet metal for both potential energy saving and electric motor power consumption reduction. Most of the reported existing pressure forming processes have limited pressure application and are mostly used for batch production. Above all, none of the existing processes use hydraulic accumulator and hydraulic transformer to save and reuse the energy or convert the system pressure and flow to the predetermined load requirement which could prevent wrinkling and fracture effect caused by low and unduly high pressure. Instead, most of the processes throttle excess fluid that is not required back to the reservoir thereby wasting excess motor energy as well as generating heat to the system. The resultant effect been the use of much energy during metal forming operation that leads to enormous financial lost to companies. It was as a result of these problems that the research was carried out. This development uses two secondary units (the hydraulic transformer) to transform a low pressure/high fluid flow into a high-pressure/low fluid flow. The use of variable speed drive (VSD) unit prevents pressure surges and ensures smooth starting and stopping of the machine. The hydraulic punch unit coupled to the hydraulic cylinder (ram) on a single action stroke performs the forming operation when the cylinder rams strikes. During ram retraction, the system saves and recycles both the hydraulic energy and generated heat back into the accumulator. The highly pressurized fluid generates a force of about (1500kN) which is used to power the punch piston for steel forming of thickness between 1.00mm-2.5mm. This operation leads to mass production of high strength, quality surface textured metallic parts within a second. The system simulation is performed using SIMULINK. The experimental results does not only agree with theoretical analysis but also appears to prove that the system is very efficient in energy saving and recuperation.
Effect of Initial Position of the Counterpunch on T-Shape Hydroforming
Authors: Teng Bu Gang , Li Kai
Published: May 2013

The loading path is crucial to the quality of forming parts in the process of tube hydroforming. The counterpunch is usually used to control the protrusion height and also to control the evolution of thickness and avoid over thinning in T-shape hydroforming. In this study, the experiments of T-shape hydroforming are conducted, in which tubular material used is stainless steel and has an outer diameter of 103mm. A fuzzy logic-based load control algorithm is developed for optimizing the loading path, and four different initial positions of the counterpunch are designed to investigate its influence on wall-thinning and the corner radius at protrusion end. The results show that the minimum thinning can be obtained with an initial position of 12.5mm, while a smaller corner radius is obtained with an initial position of 37.5mm.
An Experimental Study of Cutting Forces in Ball-End Milling of AISI H13
Authors: Ding Tong Chao
Published: May 2013

In the present study, an attempt has been made to experimentally investigate the effects of the cutting parameters on cutting forces in hard milling of AISI H13 steel with coated carbide tools. Designed based on Taguchi method, four factor (cutting speed, feed, radial depth of cut and axial depth of cut) four level orthogonal experiments were conducted. Three components of cutting forces were measured during hard milling experiments and then variance analysis was performed. Finally, the linear regression model was established.
Analysis on Milling Stability Performed under the Conditions of Positive and Negative Process Stiffness
Authors: Hsiao Te Ching , Huang Chao Yu , Junz Wang Jiunn Jyh
Published: May 2013

This paper aims at discussing chatter characteristics performed by a one-dimensional milling system having positive process stiffness and negative process stiffness. In this study, a dynamic model of the milling system is established first. An analytical form showing the critical chatter conditions including axial depth of cut, chatter frequency, critical spindle speed, etc. is formed. The analysis of process function shows that positive process stiffness occurs under most cutting conditions. However, process stiffness becomes negative when a one-dimensional milling system carries out low radial depth of cut in the direction of the feed (down milling) or semi-groove milling in the direction against the feed (up milling). Further analysis is made to explore chatter characteristics performed by the milling systems with positive process stiffness and negative process stiffness respectively. Finally, the prediction equation calculating critical chatter conditions of these two types of milling system, the range of rotation speed with high cutting stability and the range of rotation speed with low cutting stability is proposed.
Cutting Force Modeling and Prediction in End Milling Including Flank Wear
Authors: Wen Jie , Peng Fang Yu , Lin Sen , Yan Rong , Liu Yi Zhi
Published: May 2013

A mechanistic approach for the prediction of end milling including tool wear is proposed in this paper. The additional cutting force caused by increase of flank wear is considered. Total cutting force is regarded as the summation of the rake-face force and flank-face force. Cutting force coefficients are identified by the cutting tests of various cutting parameters combination on 300M steel. Then the cutting force coefficients models are established based on the cutting parameters. The prediction of cutting force obtained by numerical method is validated by the cutting experiments.
Effect of Microstructure on Cutting Force and Chip Formation during Machining of Ti-6Al-4V Alloy
Authors: Sun Shou Jin , Brandt Milan , Mo John P.T.
Published: May 2013

Dry machining was conducted on Ti-6Al-4V alloy with three different types of microstructure: globular, bi-modal and fully lamellar microstructures. The effects of cutting speed on the cutting force and chip formation were investigated. The differences in cutting force and chip morphology are found only at cutting speed lower than 100m/min. The main cutting force and chip thickness when machining Ti-6Al-4V alloy with globular microstructure are lower than these when cutting Ti-6Al-4V alloy with bi-modal and fully lamellar microstructures at cutting speed lower than 100m/min. The tendency of segmented chip formation is the highest for cutting Ti-6Al-4V alloy with fully lamellar microstructure and the lowest for machining Ti-6Al-4V alloy with bi-modal microstructure at cutting speed lower than 100m/min because of their differences in increase of shear strength with strain rate.
Experimental Study on Hardness of Titanium Alloy Ti-1023 by Milling
Authors: Yang Hou Chuan , Chen Zhi Tong , Jiang Li Ke
Published: May 2013

The titanium alloy Ti-1023 is widely used in aerospace industry, because of its low density, high strength, good corrosion resistance, etc. the integrity of the parts’ milling surfaces is of critical importance for aerospace industry. This paper aims to study the influence of the cutting speed and tool flank wear on hardness and hardening depth. The result shows that hardness and hardening depth have a significant effect on the cutting speed and the increasing of tool flank wear.
Static and Modal Characteristic Analysis of a Horizontal Machining Center
Authors: Liang Gui Qiang , Lin Mei , Guo Ting Ting
Published: May 2013

In order to get an accurate analysis results for static and modal characteristics of a machining center, finite element analysis method was taken. Taking a horizontal machining center as example, solid model was established firstly. Finite element model containing joint parameters was established in ANSYS. With the help of finite element method, static and modal characteristics of the horizontal machining center were carried out. It was concluded that the horizontal machining center has comparatively smaller static stiffness in Z direction; in order to improve modal characteristic of the horizontal machining center, the column and worktable should be paid more attention. The research results provide guidance for finite element analysis and optimization of whole machine tool.
The Analysis of Static and Dynamic Characteristic in Grinding Head of Roller Machine
Authors: Cao Jin Ling , Luo Ying
Published: May 2013

On the basis of the establishment of the three-dimensional solid model of the roll grinder grinding head spindle system, carry out finite element static analysis, with the spindle structural stress and strain diagram, study its static characteristics, carry out modal analysis in the properly simplified spindle system with the finite element method, analyze the calculated natural frequency value , study dynamic characteristics of the spindle system, realized the dynamic design of the product.
Investigation on Delamination Factor in Drilling Medium Density Fiberboards with Variable Feed Pressure Using Multi-Spindle Drill
Authors: Wang Kun , Wang Cheng , Gao Meng
Published: May 2013

Abstract．Drilling quality in manufacturing medium density fiberboards (MDF) is greatly affected by delamination. In multi-spindle drill machine, the feed is provided by feed pressure generated by air compressor. This study focus on relation between delamination and machining parameters in drilling MDF with variable feed pressure. The relation is investigated by establishing second order polynomial models using response surface methodology, and the analysis of variance (ANOVA) is employed to verify the validity of the models. It is found that the delamination factor increases with the decrease of drill hardness and with the increase of feed pressure both at entry and exit of MDF. However, at low level hardness and high level feed pressure, the delamination factor is insensitive with variation of drill hardness and feed pressure.
Parameter Recognition and Optimization of Residual Stress Prediction Model Based on Genetic Algorithm
Authors: Liu Hai Tao , Sun Ya Zhou , Shan De Bin
Published: May 2013

Building a forecast model of cutting surface's residual stress due to different cutting parameters and finding the optimal combination of cutting parameters is the demand of developing ultra precision industries such as aviation and aerospace. Owing to the limitation of the least square method and other conventional methods, genetic algorithm was introduced into the parameter identification of cutting surface's residual stress forecast model and to optimize cutting parameters. In this way, a cutting surface's residual stress forecast model of aluminum alloy is given. By contrast, genetic algorithm is more suitable to identify parameters of cutting surface's residual stress forecast model, and to guarantee the optimal cutting parameter combination.
The Effect of Tool Geometrical Parameters on Cutting Temperature Based on Deform-3D
Authors: Zhang Hua Jing , Tang Zhi Tao
Published: May 2013

The finite element method was adopted to predict the cutting temperature filed of workpiece surface when machining aerospace aluminum alloy 7050-T7451. Some key techniques such as the materials flow stress behavior, the separation of the chips with the workpiece, failure and fracture criterion, the tool-chip friction model were discussed in details. To validate the finite element model, the cutting temperature field of the chip was obtained by infrared thermal imaging system. The result revealed that the prediction model is credible. Based on the model, the effects of tool geometrical parameters such as flank wear, cutting edge inclination and corner radius on cutting temperature were analyzed.
The Nano-Cutting Mechanism Research of Polysilicon Based on Molecular Dynamics
Authors: Zhu Ying , Qi Shun He , Xiang Zhi , Xie Ling Ling
Published: May 2013

Molecular dynamics model of the polysilicon material under the micro/nanoscale is established by using molecular dynamics method, make variety of the typical defects distribute to the polysilicon model reasonable and relax the simulation model, obtain the system potential energy curves in the relaxation process and the atomic location figure after the relaxation. Conduct molecular dynamics simulation of nanometric cutting process relying on the development of simulation program, get instant atom position image and draw the cutting force curve. Discusses the typical defects impact on the polycrystalline silicon nanometric cutting process, those mainly include cutting force changes in the cutting process, potential energy changes and processed surface quality etc.
Bayesian Probabilistic Approach to FE Model Updating of Vehicle Typical Spot Weld Structure
Authors: Yao Chun Zhu , Wang Hong Yan , Rui Qiang
Published: May 2013

Finite element (FE) modeling of laser welds for dynamic analysis is a research issue because of the complexity and uncertainty of the welds and thus formed structures. A Bayesian probabilistic framework incorporating MCMC for updating the parameters of a spot weld structure model was presented, cooperation of finite element program and multiple chains sampling technology was realized, and statistical characteristics of structural parameters were obtained. Distribution ranges of the three frequencies were predicted based on parameter estimation. Numerical simulation indicates that there are little changes in standard deviations of posterior distribution compared to prior distribution, the posterior mean values are in good agreement with the corresponding measured average values. The convergence indicates the techniques feasibility and effectiveness. The present work offers an alternative approach to updating the spot weld structure parameters.
Experimental Study of Effect of Adhesives on Strength of Composites Adhesive Joints
Authors: Yang Yin Huan
Published: May 2013

Tension tests on T700/EXOPY unidirectional laminates and 3-D and six-directional braided composites single-lap adhesive joints with different adhesive types under uniaxial tensile loading are performed in the presented paper. Failure modes, strengths and load-displacement curves of two kinds of different adhesive joints are compared and analyzed. According to the experimental results, it is found that the strength of the joints of the smaller adhesive shear strength is less, in contrast, the strength of the joints of the bigger adhesive shear strength is greater, Failure shear strength average is grown 27% relatively. And the starting position of the crack is appeared at the overlap ends, and the whole joint is failed with propagation of the crack.
Orthogonal Experiment of Resistance Microwelding of Insulated Copper Wire and Phosphor Bronze Sheet
Authors: Qi Jun
Published: May 2013

The selection of welding parameter has an important effect on weld quality. In this paper, an orthogonal experiment method was used to optimize the resistance microwelding (RMW) parameters for the connection of insulated copper wire and phosphor bronze sheet. An orthogonal array with three factors (welding current, weld time and electrode force) and five levels was used. Joint breaking force (JBF) and surface appearance were selected as the evaluation criterion of the weld quality. The results show that welding current was the most influencing parameter on joint strength, while the electrode force had the most significant effect on the surface appearance. The orthogonal method was proved to be an effective method to obtain the optimum conditions for RMW of insulated copper wire.
Progressive Failure Analysis of Adhesively Bonded Laminates Joints with Spew Fillets
Authors: Yang Yin Huan
Published: May 2013

Failure prediction of adhesively bonded single-lap laminates joints with spew fillets in the overlap ends under uniaxial tensile loading is performed by progressive failure analysis method. A modified form of Hashins failure criterion by Shokrieh and maximum stress criterion are used to detect the laminate failure and adhesive failure, respectively, where a sudden degradation model is proposed to reduce engineering material constants. Five kinds of failure modes are considered. The numerical analysis of composites adhesive joints is implemented in ANSYS Parametric Design Language (APDL) with commercial finite element codes ANSYS. The error of simulation and experimental failure loads is 6.9% and the model has been validated by comparing numerical results with experimental results.
The Friction Welding Characteristic Analysis of the Al 7075-T6 According to the Spindle Speed and Upset Pressure
Authors: Lee Il Taek , Kim Hyun Sik , Park Changon , Hong Dong Pyo , Kang Hee Yong
Published: May 2013

The propeller shaft of rear-wheel drive vehicle is an axis which transfers power from an engine to rear-wheel through differential gear box. In this study, we studied the properties of friction welding required to produce the aluminum propeller shaft of lightweight rear-wheel-drive vehicle. We studied welding property to apply Al 7075-T6 aluminum yoke to automobile connects driving shaft and differential gear box. Here, solid phase friction welding method was used. In friction welding process, the principal parameter is spindle speed, up-set pressure and up-set time. We analyzed variable characteristics of friction welding strength according to the change of the spindle rate and up-set pressure. Friction welding strength was analyzed with ultimate tensile strength test with universal testing machine (UTM). The Al 7075-T6 was used as the round bar of the diameter of 25mm. The ultimate tensile strength was 552.3 MPa. It is 94% of ultimate tensile strength of pure Al 7075-T6 material. The main parameters of characteristics are discussed in detail based on analysis of the main effects plot and multi-vari chart. Finally, the core factors to get the maximum effect of friction welding investigated.