Applied Mechanics and Materials Vols. 34-35

Abstract: The stability and vibration of fluid-filled pipes are important in many engineering situations and have been extensively studied. In this paper, coupled fluid–structure analysis is carried on by wavenumber prediction. Pipe equations for axisymmetric wave motion are derived, and two kind of axial waves are studied analytically at low frequencies, i.e., , which is a predominantly fluid-borne wave, and , is predominantly a shell wave. Numerical results are subsequently given to show the definitely influence of the pipe and the fluid.

Abstract: In this paper, energy absorption characteristics of PVB laminated windshield subject to human head impact are studied. SHPB method is carried out to obtain the constitutive relationships of PVB laminated glass in dynamic behavior. With the SHPB results embedded, finite element simulation is used to study the dynamic behavior of PVB laminated windshield. In particular, energy absorption characteristics are investigated. Two parameters for measuring the energy absorption property of windshield are suggested, i.e. loss of head velocity and HIC value and a parametric study is carried out to see the effect of impact velocity and impact position. Results can shed lights on the research of energy absorption capability of PVB laminated windshield.

Abstract: It is an expectation of most of the numerical control products manufacturer that have a powerful controller with whole won intellectual property and without restriction from other companies. The paper introduces a new type of motion controller that based on ARM and EtherCAT field bus. It concludes the analysis and porting method of the EtherCAT soft master source code, and how to modify the driver of dm9000 to make EtherCAT master works correctly. It also gives an example to confirm the reliability of the controller. Since ARM has an open architecture, EtherCAT soft master does not depend on any special hardware card, and Linux OS is an open source system, this controller has open and flexible characteristic both on hardware and software.

Abstract: Drum brake is a braking part which is widely used on heavy truck. The distribution and dimension of contacting pressure and contacting area between friction linings and brake drum have important influence on braking performance. Entire contact theory in this article was found based on the conditions that the outside radius of linings was equal to the inside radius of drum. The relation between the corresponding points on contact surface and the angle which lining rotated around support pin axis was calculated based on entire contact theory. The radial deformation, pressure distribution, contact area of linings and the brake performance were analyzed in the condition of entire contact theory.

Abstract: This paper is based on the on-line measuring system which is made up of machine center, probe and computer. First it introduces briefly on-line measuring system, then analyses information flow model and construct of the system, using VC++6.0, ACCESS database and OOA design idea compile the software. At last, we carry through an experiment using the software system and coordinate measuring machines validate the result.

Abstract: Mechanical property of coating under the micro-contact load such as impact and sliding wear significantly influence the reliability of surface coating. In order to research the influence, a contact model between the rigid multi-asperity surface and coating was found based on the G-W model in the background of Thermal Barrier Coatings(TBCs) used in aircraft engine blade. The distribution of stress in subsurface of the micro-contact process was analyzed based on the theories of contact mechanics and tribology with the elasto-plastic finite element method. The effect of coating thickness, elastic modulus, yield strength on the distribution of residual stress for TBCs was investigated. It conclude that primary reason of coating failure are cumulation of plastic deformation and excessive interfacial stress. The results are significant for studying the life and final spallation of TBC system and other coating.

Abstract: This research is to find a design method for the large scale and complex product system. Thus, we made an approach to possibly better solution with limited time, limited resources and limited costs. This paper aims to find a method to quantify the solving process of the first stage in the concurrent design – “task decomposition”, in order to make preparations necessary for the next two stages -“concurrent task process” and “convergent coordination”. According to product's functional unit, we first decentralized complex product system into sub-modules. Then determine the importance and coherence among these sub-modules by using analytic hierarchy (AHP). Combining the results of the two judgments, we further classify the sub-modules to form distributed sub-systems, so that different design teams can work more effectively and more efficiently during their respective period. Finally, we verify the usefulness and effectiveness of the distributed method with an example of design task decomposition in servo press.

Abstract: This paper presents a life cycle assessment (LCA) method in different design process. This method can help product designers to make more environmental friendly design decisions in the design process. In this method, product’s LCA model is established in product conceptual design phase with the aid of decision matrix. Thereafter, the model is improved in the latter design phases, especially in product detail design phases. In this process, with the help of LCA software, designers can evaluate different design options and get LCA results when necessary to guide the design process. Finally, a case study of designing a coffee pot is provided in this paper to illustrate the efficiency and effectiveness of this method. The case study shows that the method performs very well in the design process. It can be used to help designers to make more environmental friendly design decisions.

Abstract: This paper proposed a fault diagnosis based on multi-sensor information fusion for rolling bearing. This method used the energy value of multiple sensors is used as feature vector and a binary tree support vector machine (Binary Tree Support Vector Machine, BT-SVM) is used for pattern recognition and fault diagnosis. By analyzing the training samples, penalty factor and the kernel function parameters have effects on the recognition rate of bearing fault, then a approximate method to determine optimum value are proposed, Compared with the traditional single sensor by using the components energy of EMD as feature, the results show that the proposed method in this paper significantly reduce feature extraction time, and improve diagnostic accuracy, which is up to99.82%. This method is simple, effective and fast in feature extraction and meets the bearing diagnosis requirement of real-time fault diagnosis.

Abstract: As the poor generability of special sensor support frame and the inconvenience of signal acquisition in the process of common fault diagnosis for cracked rotor, a new fault diagnosis method is presented in this paper. this method takes the basement of rotor test rig as the monitoring objects and makes feature fusion for time-domain statistics of multiple sensors using SVM (support vector machine). The result of experiment showed that the method using the multi-sensor signal fusion technology collected from the basement of machinery has the advantages of better diagnostic precision for rotor crack diagnosis, furthermore, it supplies a new way for rotor fault diagnosis.