Applied Mechanics and Materials Vols. 117-119

Abstract: Stress-strain is commonly used in engineering; however the real stress-strain is more used in the test and exploitation of new product. ANSYS finite element software is adopted in this study, stress-strain of the tensile sample of the sheet in different stage is calculated under the 10mm displacement load, stress-strain curve is obtained, and the engineering and the real stress-strain are analyzed. The results show that simulation data are in accordance with the measured ones, the error is less than 3%, which proves that the model is the rational.

Abstract: 3kW two poles induction motor with compound cage rotor is illustrated in this paper, and 2-D thermal stress field of induction motor rotor is calculated and analyzed by finite element. Contrasting with common induction motor, induction motor with compound cage rotor has specific rotor shot shape and the bar is comprised of the upper compound material and the lower cast aluminium, which cause distribution of thermal stress is special. The motor with the rotor shot of compound material laid at single site is chosen to analyzing. The maximum thermal stress in the bar is calculated at different load, and the distribution of thermal stress in the bar is analyzed at rate load. The law of distribution of thermal stress in the bar has same reference value for designing new type of induction motor.

Abstract: Based on a series of tests and elastic-plastic contact finite element analyses, a sharp indentation method for predicting the constitutive relationship of metallic materials was presented. Dependent on the dimensionless linear relationship which is independent of the hardening index n, a forecasting formula of constitutive parameters can be gotten and its form is much terser. The test results and finite element calculations show that, the predicted stress-strain curves are in agreement with the uniaxial tensile test results. The validity and precision of this method was certified by in-dentation tests on kinds of different materials.

Abstract: Because of rock slope,surface Mine is full of danger. In this paper, the monitoring system configuration and data processing are discussed in combination with GPS monitoring and date analysis of slope deformation in an Iron Mine in order to seize the rule of rock deformation and provid a more reliable basis for taking measures for control the rock Stability.The dynamic monitoring system and rock Stability evaluation method are developed so as to resolved the rock Stability in the surface mine that would be underground mining.Which can also provide for the design plan、data processing 、technical measures of the control the rock Stability and promote the continuable development of the Surface Mine.

Abstract: This article analyses the theories of two methods of matrix displacement and finite element, and the application of calculation in the actual structure. Then it explores the subtle differences between them: Matrix displacement method can only be used for analysis with known unit nodes force-unit nodes of the relationship between the displacement of the truss structure, and not the continuous body structure. The major differences between both are the establishment of the basic principle and solution of the emphasis. Establishing total stiffness matrix according to the geometric property of the structure and then forming integral force vector via loading conditions when matrix displacement method is used to solve the unit fixed-end force. It’s necessary to stack fixed end force; While finite element method mainly bases on the known load and the material nature of structure after structure discretization. Node force or node stress is directly got by the derivation of displacement, but the fixed end force is lost, which dropping the accuracy of the stress. To solve plane frame structure and get structural internal force, the distinguish is checked on the example.

Abstract: The hardness of Mn13 can increase if taking asynchronous cold rolling technique .The mechanism of work hardening after asynchronous cold rolling is analyzed in depth by studying the microstructure and electron diffraction pattern with optical microscope, transmission electron microscope and X-ray electron diffract photographic camera. The research will make a contribution to theory and practice of Mn13.

Abstract: Material deformation measurements are divided into two main classes: contact type measurement and non-contact type measurement. The principles of strain gauge contact type extensometers in small range and large range measurement, non-contact video and non-contact laser extensometers are described, respectively. Furthermore, advantages and disadvantages of these extensometers are reviewed. The contact type extensometers provide a high level of measurement accuracy, but the knife edge is easily damaged during the fracture of high stiffness materials; the total deformation process is not measured unless knife edge is not unloaded post-fracture; meanwhile, the reversal phenomenon is accompanied in tensile test. Accordingly, the resolution of the reversal phenomenon is discussed; Non-contact video extensometers may be used up to the material breaking point without damage, even when testing specimens that exhibit whiplash, but marks on specimens deform following specimens deformation in tensile test, and marks are not automatically and accurately tracked; Although, non-contact laser extensometers provide a higher level of measurement accuracy and wide range of application, it is expensive. On the basis of these discussions, a novel materials deformation measurement method based on laser mark automatic tracking is presented. This method has advantages of simple, high accuracy and wide range of application.

Abstract: Atomic absorption spectrometry (AAS) is adopted to determine the contents of typical metal elements (Fe, Cu and Cr) in automatic transmission fluid (ATF) in this paper. The analysis and experimental results demonstrated that the contents of typical metal elements in ATF are higher as the running distance of the tractor is increased even though under the condition of the same driver and the same tractor. The contents of the metal elements, Fe, Cu and Cr, follow a specific function, of which correlation coefficient are respectively 0.998, 0.9974 and 0.9952. Consequently, the nondestructive detection for major components of automatic transmission is realized real-timely and reliability by the means of determining the contents of Fe, Cu and Cr in ATF using AAS quickly and accurately.

Abstract: Aiming at the strip edge drop control, the three dimensional finite element roll system models were built. From the point of the burdened load and deformation of the roll system, the reason which caused the strip edge drop and its composing were analyzed, and the critical width was proposed to control the strip edge drop. Based on the FEM analysis and industrial experiment, the VCR (Varying contact backup rolls) matching the EDW (Edge drop control work rolls) was designed and proposed independently. The application of such rolls gives better mill crown control ability, a high performance of work roll bending force and the improved strip edge drop, crown and flatness quality.

Abstract: We discuss the existence of periodic positive solution of one kind of multiple time-delay functional differential equations with the cone theory and fixed index method in semi-order Banach space of nonlinear functional analysis.