bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural Modification Simulation: Sensitivity Analysis and the Reanalysis of Modified Structure
Authors: Li Debao , Li Fangze , Xu Peiming 
Published: April 2021

Abstract
This paper deals with the dynamic modification simulation of the structure. The expressions of sensitivity analysis of the system with non-proportional damping and proportional damping are derived at first. As for the reanalysis of modified structure, here we deal with the system to which the modification do not cause any change of the degrees of freedom. Transfer function analysis method and the method of twice coordinate transformation are expounded. As a successful example, the modification simulation of the frame of a dump truck is explained.
Structure Damage Detection via the Behavior of Substructure
Authors: Wang J. H. , Liou C. S. 
Published: April 2021

Abstract
A mechanical system generally consists of many substructures. However, it is impossible to observe the dynamic behavior of any substructure directly when the whole structure is in operation. A method was proposed in this work to determine the FRFs of a substructure by using the measured FRFs of the whole structure and the priorly known FRFs of another substructure With this method, one can detect the structural damage more easily by observing the change of the FRFs of the damaged substructure.
Recognition of Bearing Faults of the Same Kind
Authors: Bao Ming , Zhao Chun-sheng 
Published: April 2021

Abstract
Condition monitoring has gained much acceptance because of the reduction of maintenance expenses and the increase of rate of equipment utilization. It is very important that the serious degrees of machinery faults is correctly predicted. Two faults in a bearing part is, of course, more serious than the single fault is. If the features of bearing faults of the same kind are not recognized, faults of the same kind are, then, mistaken for a single fault, the serious consequences may be caused. The features of bearing faults of the same kind are presented and the illustrations are given in the paper. Meanwhile, the correct equation of roller’ s fault characteristic frequency is expounded conveniently.
A New Diagnosis Method Based on State Spectrum and its Applications
Authors: Zhao Zhen-Ying , Cha Jian-Zhong , Zhu Meng-Zhou , Tang He 
Published: April 2021

Abstract
Based on the time series, a new concept of spectrum representing the system state, called State Spectrum, is developed through the analysis of the varying principles of self-regression coefficients in this paper. The physical explanation of the spectrum, the meanings of the spectrum’s longitudinal and transverse coordinate and the way to use them in the state recognition and fault diagnosis of mechanical devices have been discussed in details. some experiments have carried out and the results indicate that the proposed new approach is very promising in fault diagnosis of mechanical devices.
The Application of Principal-Component Analysis in Gear Fault Diagnosis
Authors: Zhao Zhen-Ying , Cha Jian-Zhong , Tang He , Zhu Meng-Zhou 
Published: April 2021

Abstract
In this paper, the application of the principal-component analysis method in fault diagnosis is explored. Characterized as fast and precise, this method can be directly used for analyzing gear noise and vibration signals in time domain. The principal component method and its1 error occur-ring in the calculation are theoretically discussed in detail. A program for implementing this method has been developed and the experiments for gear fault diagnosis have been carried out with satisfactory results.
Dynamic Detection of Damage in Structure
Authors: Mao Qinghua , Shen Xiaofeng 
Published: April 2021

Abstract
When a damage exists in a structure, the dynamic characteristics of the structure are changed. A great deal of effort has been elaborated to determine the position and the amount of the damage by using the natural frequencies and the mode shapes. In this paper, a theoretical method is given to detect the damage in a structure based on the changes of its natural frequencies and the mode shapes. After determining the location of the damage, a correcting factor describing a reduction in stiffness of damaged element gives the amount of the damage. This method is proved on two examples of beam structures.
Effect of Operating Speed in Diagnosis of Gear Faults
Authors: Özgüven H. Nevzat , Yalçintaş Melek 
Published: April 2021

Abstract
This paper presents the effect of the operational speed of gears on the vibration signals measured at bearings for gear fault diagnosis purposes.The information available in literature is usually for relatively low speeds of gears. As it is very difficult to study experimentally the vibration of high speed gears with controlled specific gear faults, computer simulation is used in this work. Nonlinear dynamic analysis program developed in an earlier study is used in simulating the dynamic behavior of spur gears with several different gear faults, and an FFT algorithm is used to generate the frequency spectrum of bearing vibrations. Three types of gear faults are discussed in this paper: uniform profile error, eccentricity, and local faults on a single gear tooth. The model used in the analysis is nonlinear and includes several important effects such as variable mesh stiffness, backlash, separation of teeth, shaft and bearing dynamics. Spectra of the bearing vibrations for gears with well known faults are used to verify the computer simulation approach employed. Then the effect of the operating speed of gears on the diagnosis of these faults are studied by obtaining bearing vibration spectra at different gear speeds. It is concluded that some frequendy used and well known diagnostic rules may not apply at high speeds.
Control and Optimization of Structures Using Spectrum Analysis
Authors: Drakatos P. A. , Drakatos S. P. 
Published: April 2021

Abstract
In this paper diagnostic methods are applied is order to study the behaviour of the structure as they are being excited and response to the exciting reasons.
For this purpose, measurements are taken on the field of time and form the, using spectrum analysis., spectra of frequency are taken for studying to the amplitude of the frequencies or to the position of each frequencies or to the position of each frequency of the field of frequencies. It is obvious there is a connection between the condition of stress and strain of the structure between the condition of stress and strain of the. structure and the position and the amplitude of frequencies that are taken form the analysis of the measurements.
So controlling the frequencies for some kind of measurments it is easy to control the condition of the structure.
Otherwise using simulation and optimization methods it is possible first to build a model and after to examine this model for several types of fatigue.
Taking always the spectra of measurements and comparing them by themselves it is possible to find the optimal model and taken to apply the conclusions to the structure.
Finally it could be said that this work can be applied during the stage of design of the structures as it helps by control. The simulating models in order to find the optimal structure.
Optimal Design of Vibration Absorber Systems Supported by Elastic Base
Authors: Ashrafiuon Hashem 
Published: April 2021

Abstract
This paper presents the effect of foundation flexibility on the optimum design of vibration absorbers. Flexibility of the base is incorporated into the absorber system equations of motion through an equivalent damping ratio and stiffness value in the direction of motion at the connection point. The optimum values of the uncoupled natural frequency and damping ratio of the absorber are determined over a range of excitation frequencies and the primary system damping ratio. The design parameters are computed and compared for the rigid, static, and dynamic models of the base as well as different levels of base flexibility.
Control of Asymmetric Systems Using Complex Modes
Authors: Fan G. W. , Nelson H. D. 
Published: April 2021

Abstract
The complex modal approach is introduced for the optimal vibration control (Linear Quadratic Regulator) of high-order nonsymmetric discrete systems. An LQ regulator is designed based on a reduced-order model obtained by neglecting high-frequency complex modes of the original system. The matrix transformations between physical coordinates and complex coordinates are derived. A 52 degree-of-freedom finite element based rotordynamic system is used for illustration. Simulation results show that an LQ regulator based on a reduced-order system obtained by using normal modes of a high-order system with asymmetric models can possibly destabilize the original system i.e., the spill-over problem (Ulsoy, 1984), however, this problem might be avoided by applying complex modes which provides a more accurate reduced-order model than obtained by normal modes. Comparison of the reduced-order models using normal modes and complex modes is presented. Frequency, time transient and steady state responses of the controlled and uncontrolled systems are also shown.
Digital Control Algorithms for Microgravity Isolation Systems
Authors: Sinha A. , Wang Y.-P. 
Published: April 2021

Abstract
New digital control algorithms have been developed to achieve the desired transmissibility function for a microgravity isolation system. Two approaches have been presented for the controller design in the context of a single degree of freedom system for which an electromagnet is used as the actuator. The relative displacement and the absolute acceleration of the mass have been used as feedback signals. The results from numerical studies are presented. It has been found that the resulting transmissibility is quite close to the desired function. Also, the maximum coil currents required by new algorithms are smaller than the maximum current demanded by the previously proposed phase lead/lag method.
A Study on Active Dynamic Absorber
Authors: Seto Kazuto , Furuishi Yoshirou 
Published: April 2021

Abstract
Although it is known that active dynamic absorbers are useful for controlling vibration of structures, the design method for popular usage has not yet been established. This paper proposes the design method of the active dynamic absorber by use of the LQ optimum control theory. First, nondimensional representation of the state equation of the structure and active dynamic absorber system, the state feedback gain matrix, and the weight matrix, respectively, are constructed to obtain a generality. Secondly, the relationship between the vibration control effect and parameters of the weighting matrix are made clear for designing. The design data are prepared as the nondimensional root locus, frequency response, and impulse response charts. Effectiveness of the active dynamic absorber designed through the method is demonstrated experimentally.
Flexural Vibration Response of Beams With General Boundary Conditions: A Transfer Matrix Approach
Authors: Önsay T. 
Published: April 2021

Abstract
The wave-mode representation is utilized to obtain a more efficient form to the conventional transfer matrix method for bending vibrations of beams. The proposed improvement is based on a phase-variable canonical state representation of the equation governing the time-harmonic flexural vibrations of a beam. Transfer matrices are obtained for external forces, step-change of beam properties, intermediate supports and for boundaries. The transfer matrices are utilized to obtain the vibration response of a point-excited single-span beam with general boundary conditions. The general characteristic equation and the transfer mobility of a single-span beam are determined. The application of the analytical results are demonstrated on physical structures with different boundary conditions. A hybrid model is developed to incorporate measured impedance of nonideal boundaries into the transfer matrix method. The analytical results are found to be in excellent agreement with experimental measurements.
Experimental Research on Longitudinal Wave Velocity of Fiber Glass Rod and its Internal Viscous Damping
Authors: Hu Yu-Ren , Xu Jun 
Published: April 2021

Abstract
Fiber glass rod (i.e. FGR) is an uniaxial fiber reinforced plastic. In the movement of the rods, some dynamic characteristics such as the wave velocity and the damped coefficient are most important dynamic factors in analysis of the dynamic response of the rods. Generally, FGR are composed of two materials, fibers and resins. The particularities of the parameters for the wave velocity, etc of FGR are mainly depend on these two materials of different properties. This paper studies longitudinal velocity for FGR theoretecally and measure it by vibration method. The viscous damped coefficient is also measured by the theory of viscoelasticity. This paper presents that the viscous damped characteristic of material is mainly depend on the coupling mass between the rods.
Vibration Isolation in a Microgravity Environment
Authors: Alexander Richard M. , Gerhold Carl H. , Atwood Clay B. , Cordera Joseph F. 
Published: April 2021

Abstract
Many in-space research experiments require the microgravity environment attainable near the center of mass of the proposed Space Station. Since dynamic disturbances to the surrounding structure may undermine an experiments validity, isolation of these experiments is imperative. Analytical and experimental work has been completed in developing an isolation system which allows the payload to float freely within a prescribed boundary while being kept centered with forces generated by small jets of air. An experimental setup was designed and constructed to simulate the microgravity environment in the horizontal plane. Results demonstrate the air jet control system to be effective in managing payload oscillatory response. An analytical model was developed and verified by comparing predicted and measured payload response. The mathematical model is used to predict dynamic payload response to disturbances likely to be present in the Space Station.
The figure shown below is a schematic of the test setup to be discussed during the presentation.
Three-Schema Implementation in STEP: Standard for the Exchange of Product Model Data
Authors: Yang Yuhwei 
Published: April 2021

Abstract
This paper describes the development architecture of the evolving international product data standard, PDES/STEP. The focus of the paper is to present the influence of the three-schema concept and its implementation in STEP.
The fundamental requirement for any specification to be useful is that it must support its intended applications. PDES/STEP, as the future industry standard for product data communication, must be structured to provide flexibility to allow different implementation scenarios, e.g., sequential file exchange or controlled access of shared database implementations. In order to provide this required implementation flexibility, STEP is currently developed with an architecture that facilitates multiple specifications.
The STEP Integrated Architecture organizes both the resource models and models of the STEP Application Protocols. The STEP Integration Architecture presents an implementation that resembles elements of the ANSI/SPARC recommended three-schema model.
A PDES Model for Microwave Modules
Authors: Bahadur Sudhanshu , Harhalakis George , Hosier Robert N. , Minis Ioannis 
Published: April 2021

Abstract
This paper presents a novel application of the Layered Electrical Product (LEP) model of the PDES (Product Data Exchange specification using STEP) standard. All three levels of the LEP model are developed for a typical microwave module (MWM). The latter is comprised of a component layer, the artwork, an insulation layer and a ground plane, which is a complex mechanical part. The nature of the ground plane necessitated the enhancement of the first level of the model to include three-dimensional topological entities. Consequently, although the artwork and insulation layers are represented in two-and-a-half dimensions, (which is common practice in the case of Printed Wiring Boards), the ground plane is modeled using the three-dimensional PDES Geometrical and Topological models and the Form Features model. Level II includes the electrical entities of the MWM. New conventions that are necessary to represent particular features of the MWM have been proposed and applied. Based on the intention of PDES, design information that is closely related to manufacturing concerns has been represented in Level III of the model. Both the proposed structure and the contents of this level for MWMs are presented. Material specifications, mechanical features and design specifications for the manufacture of joins are included. Finally, potential applications of the LEP model and especially of Level III in automated process planning and producibility assessment are discussed.
Designing an Engineering Database for Telephone Networks
Authors: Danielson Scott G. 
Published: April 2021

Abstract
An engineering database modeling telephone outside plant networks is developed. Semantic and relational database design methodologies are used with the semantic data model developed based on an extended entity-relationship approach. This logical model is used to generate a normalized relational data structure. This database holds engineering data supporting engineering analyses, engineering work order generation procedures, and network planning activities. The database has been linked to separate network analysis programs and CAD-based network maps by a database application.
A Computer-Aided Analysis System With DBMS Support for Fiber-Reinforced Thick Composite Materials
Authors: Spainhour Lisa K. , Rasdorf William J. , Patton Edward M. , Burns Bruce P. , Collier Craig S. 
Published: April 2021

Abstract
The broad scope of the research described herein is the integration of several components of engineering software using a relational database. More specifically, a conceptual finite element material preprocessing system for fiber-reinforced composite materials was studied. In this computer-aided analysis (CAA) system, a materials database is integrated with several software components, including commercially available finite element analysis (FEA) programs and preprocessors, and tools for the design of laminated composite materials.
The focus of the system is on the integration of two- and three-dimensional composite materials data into several finite element analysis programs. Particular attention is given to analysis and design of components and structures using thick composite materials. Many engineering applications exist for thick composite structures; however, they have received less critical attention than the thin composite structures often used in aerospace applications. The primary objective of the composites analysis system is to enhance data transfer between and interaction among several engineering software programs with a minimum of user interaction.
This paper describes a specific implementation of a computer-aided analysis system that achieves this objective, detailing the need for the system and describing each of its components, including a composite materials database. The capabilities of the integrated system are discussed, including tasks such as composite laminate design, data entry, report generation, and interface file generation, performed in support of the finite element analysis capability. A major focus of the paper is on the twofold role of the materials database in the analysis system, as both a passive data repository and as a dynamic data transfer mechanism. The use of interface programs and direct integration techniques are discussed in the context of passing materials data between the user and the database, and between the database and the various system components or application programs.
The Contribution of Data Modeling to the Future Development of CAD/CAM Databases
Authors: Eastman Charles M. 
Published: April 2021

Abstract
Data modeling is proposed as a means to address the complexities of CAD/CAM databases. The distinctions between product data models and those in general databases are reviewed. A data model, called EDM, is presented that incorporates features that are defined to response to these differences. A review is given of data modeling analyses carried out thus far regarding database extensibility, including support for open-ended knowledge domains.
CIM Dictionaries: An Evolutionary Approach to CIM Data Integration
Authors: Weissflog Uwe 
Published: April 2021

Abstract
This paper provides an overview of methods and ideas to achieve data integration in CIM. It describes a dictionary approach allowing participating applications to define their common constructs gradually as an additional service across application systems. Because of the importance of product definition data, the role of PDES/STEP as part of this dictionary approach is also described.
The technical concepts of the dictionary, such as schema mapping, semantic data model, user methods and the required additions within participating applications are explained. Problems related to data integrity, data redundancy, performance and binding of dissimilar software components are discussed as well as the deficiencies related to today’s data modelling capabilities.
The added value an active dictionary can provide to a CIM environment consisting of established applications in heterogeneous environments, where migration into one standardized homogeneous set of CIM applications is not likely, is also explained.
Using Information Theory to Model Design Processes Supported by Information Systems
Authors: Rangan Ravi M. 
Published: April 2021

Abstract
This paper describes the use of information theory to model the interactions between various design agents in a design/manufacturing organization. In typical multidisciplinary design environments, the design attribute space is constrained by the requirements and compatibility conditions introduced by interacting disciplines. A key factor toward efficient design lies in the recognition of this constrained design space, and in communicating this to the designers during the initial stages of the design process. As a result, engineering information systems that support the multidisciplinary design activities must incorporate these constraints, and provide designers with a uniform mechanism that will assist design attribute awareness, provide decision discriminators and model design attribute dependencies.
The concept of entropy as defined in information theory will be used to quantify both the information content of a design as well as the design attribute space. Specifically, we shall investigate how this model may be used for a class of parametric design problems.
Adding Prolog Rules and OOPs Inheritance to Legacy Databases
Authors: Goldschmidt Art , Gangopadhyay Dipayan 
Published: April 2021

Abstract
We present a viable approach to add rules capability or object orientation to legacy databases.
Using a combination of language compilation, run-time trigger mechanisms and inter-language call facility, we integrate an object-oriented logic programming language, called OOLP, with an existing CIM Database System Product, IBM’s CIM CDF.
The result is a system that provides storage management of complex objects, rule-based validation, object oriented knowledge modelling and declarative query capability.