Papers by Keyword: Thermo-Mechanical Analysis (TMA)

Paper TitlePage

Authors: Hao Jie Lv, Guo Qing Hu, Xing Ye Wang
Abstract: In order to reveal the temperature dependence of a touch mode capacitive pressure sensor, temperature dependence of material parameters of the sense have been studied. Using Finite Element Method (FEM) to simulate and solve capacitance, the results show that the relation of capacitance and temperature is almost linear in touch state of the sensor. At the same time, temperature sensitivities under different pressure are slight difference, which are 0.0056pF/K and 0.0040pF/K, respectively. Therefore, the high-temperature performance of the sensor is greatly outstanding.
Authors: Pablo A. Muñoz-Rojas, M.A. Luersen, T.A. Carniel, E. Bertoti
Abstract: Porous materials have gained wide use in high level engineering structures due to their high stiffness/weight ratio, good energy absorption properties, etc. Frequently, thermal behavior is also an issue of concern and optimized multifunctional thermo-mechanical responses are sought for. This paper presents the application of a hybrid two-stage method for achieving an optimized layout of periodic truss-like structures in order to obtain a good compromise between thermal and mechanical elastic properties. The first stage employs a derivative free optimization method, which explores the design space, not getting trapped by local minima. The second stage uses a derivative based optimization algorithm to perform a refinement of the solution obtained in the first stage.
Authors: Miao Quan Li, L. Long, X.L. Li, H. Yu, C.L. Chi, G.H. Wen
Abstract: In this paper, the flow stress model has been established based on the isothermal compression data at deformation temperature of 800~1050oC, strain rate of 0.001~0.1 s-1 with the help of the Zener-Hollomon parameter and the Arrehnius’ equation. For the forging of Ti-6.0Al-2.0Zr-1.0Mo-1.0V alloy with 3.0 mm in thickness and 66.0 mm in height, the equivalent stress, strain, strain rate distribution and temperature rise in the superplastic extrusion process have been simulated through FEM. The simulated results show that the punch velocity has significant effect on the equivalent stress, temperature rise and extrusion load.
Authors: Dillip Kumar Biswal, Dibakar Bandopadhya, Santosha Kumar Dwivedy
Abstract: Till to date, fabrication of Ionic Polymer-Metal Composites (IPMC) are carried out successfully using noble metal such as platinum/gold as the surface electrode. In this work we have proposed cost effective fabrication method for IPMC actuator using non-precious metal electrode of silver (Ag). Chemical decomposition method is followed using Nafion as the ion exchange membrane to fabricate pure Ag-electrode IPMC. Microscopic and morphological analyses reveal that, silver particles penetrate well through the surface of Nafion membrane. The bending deformation measurement and analysis of the thermo-mechanical properties of the fabricated IPMC is carried out. The experiment results and performance of the IPMC actuator confirm that the fabrication of pure Ag-IPMC is feasible and can be used as artificial muscle material.
Authors: Sung Pil Jung, Hyun Seok Song, Tae Won Park, Won Sun Chung
Abstract: Thermal energy generated by the friction between the disc and pad is transferred to both components and causes thermal expansion of material of each component, and futher affects the friction contact condition. This is the main factor of the thermoelastic instability (TEI) of a disc brake. In this study, TEI is analyzed using the finite element analysis technique. Three dimensional thermo-mechanical analysis model of the disc brake system is created. An intermediate processor based on the staggered approach is used to exchange analysis results: temperature, friction contact power, nodal displacement and deformation. Disc thickness variation (DTV) and temperature distribution of the disc are calculated, and the tendency and meaning of the results are discussed.
Authors: Juan Yang, Qin Qin Liu, Chuang Liang Zang, Xiao Nong Cheng
Abstract: Negative thermal expansion (NTE) material ZrWMoO8 was prepared by hydrothermal method. The phase structure and morphology of the obtained precursor and final product were examined by XRD and SEM, respectively. To study its negative thermal expansion property, two methods were utilized. One is based on the in-situ XRD results and the thermal expansion coefficient (CTE) was calculated by the cell parameters obtained at different temperatures. Another is based on the thermo-mechanical analysis (TMA) and the CTE was calculated by the length of ZrWMoO8 bar at different temperatures. The differences between these two methods were also discussed.
Authors: V. Cazajus, B. Lorrain, H. Welemane, Moussa Karama
Abstract: The framework of this study is the thermo-mechanical analysis of the brazing process of ceramic metal assemblies. The thermal expansion gradient between ceramic and metallic materials leads to the development of residual stresses during the cooling phase of the brazing process which induce consequently an important reduction of the strength of these composite structures. In the present work, numerical simulations are performed in order first to predict the residual stresses distribution after the brazing process and in a second step, to study their influence on the tensile strength of metallized ceramic seals. Results obtained are compared with experimental tests.
Authors: Emidio Nigro, Anna Ferraro, Giuseppe Cefarelli
Abstract: Fire Safety Engineering can be defined as a multi-discipline based on the application of scientific and engineering principles to the effects of fire in order to reduce the loss of life and damage to property by quantifying the risks and hazards involved and provide an optimal solution to risk mitigation. The correct identification of fire scenarios is the central stage in the process of the structural fire design. A design fire scenario is the description of the spread of a particular fire with respect to time and space. In the process of identification of design fire scenarios for the structural fire safety check, all fires must be assessed realistically, choosing those most severe for the structural response. This paper is devoted to evaluate the influence of fire scenarios on the structural behaviour of composite steel-concrete buildings. In order to that, an office building subjected to different fire scenarios was considered. In particular the fire scenarios were defined by both standard fire (prescriptive approach) and natural fire (performance approach). Finally, a comparison between the prescriptive approach and the FSE approach is presented.
Authors: Lahlou Dahmani, Rachid Mehaddene
Abstract: In this paper are illustrated the principal aspects connected with the numerical evaluation of thermal stress induced by LNG (liquefied natural gas) in a concrete tank. In order to investigate the thermal induced tensile stresses, the ANSYS finite element code has been employed for performing a sequential, non linear, transient thermal-structural analysis, taking into account the thermal dependant properties of the concrete such as thermal conductivity and specific heat. Temperature distribution data of thermal analysis is required in the coupled field analysis finally to obtain and analyze thermal stresses.
Authors: Jian Jun Sha, Jing Wang, Xiao Wei Gao
Abstract: Thermo-mechanical analysis for W/Cu-alloy joints with different interlayer thickness of OFHC-Cu was carried out by FEM calculation. The result indicated that the compliant OFHC-Cu can significantly reduce the magnitude and concentration of stress and plastic strain, but a weak influence on the temperature distribution. A comparison was made on the residual stress and plastic strain between the fabrication and operation conditions. It was found that the optimum thickness of OFHC-Cu is 1.0 mm in current analysis conditions.
Showing 1 to 10 of 12 Paper Titles