Thermal Shock Problem Of Temperature Field Analysis And Optimization Design

More attention is paid to the thermal shock effects on the manufacturing process of device components in the field of high-tech such as micro-electronic technology, laser technology, nuclear technology and space navigation. The design of coupled thermal shock-structural system is very common in engineering, especially in the area of astronautics, aerospace, chemical industry and the design and manufacture of the electronic equipment, micro-electronic-mechanical system, etc. Based on the numerical analysis, the sensitivity analysis and design optimization of thermal shock problem are important research area with wide practical background. Therefore the research of temperature field analysis and thermal design optimization for thermal shock problem will be of great significance in theory and engineering.This paper studies the numerical methods of the temperature field and design optimization for thermal shock problems. And the method of parametric identification is presented based on the sensitivity analysis and design optimization. The methods of this paper have been implemented in the large-scale software of finite element analysis and structural design optimization JIFEX. The thesis consists of three main parts. The first part is the analysis of temperature field for thermal shock problems, and the thermal wave effect is discussed in detail. The second part is devoted to the sensitivity analysis and structural design optimization for thermal shock problems. The last part presents the soution methods based on the sensitivity analysis for parameter identification of inverse thermal shock problems. The following are the contents:In chapter 1, the engineering background of thermal shock problems is firstly summarized. Then the traditional methods based on the Fourier theorem and the non-conventional methods considering the non-Fourier effect are introduced. In the following, the research developments of thermal-structural design optimization and sensitivity analysis are reviewed. Then the software platform of this paper's work-the large-scale software system of finite element analysis and design optimization JIFEX are introduced and so are the Sequential Quadratic/Linear Programming Algorithm. Finally is the summary of the brief description of the research in this thesis.In chapter 2, in additon to the introduction to the parabolic heat transfer model, the attention is specially paid to the hyperbolic heat transfer model based on the non-Fourier theorem and the characteristic of hyperbolic model for thermal shock problem are discussed as well.In chapter 3, the Finite Element method in space field and the Newmark method in time field are employed to solve the hyperbolic heat transfer equations. Taking the planar four-node isoparametric element as example the detailed finite element formulations are developed. By the comparisons between the acute-transient heat transfer and weak-transient heat transfer, the thermal wave effect implied by the hyperbolic equation is evaluated in detail. The numerical examples validate the accuracy of the method in this paper.In chapter 4, the methods of sensitivity analysis for thermal shock problem are discussed. Both the direct method and adjoint method for parabolic heat transfer equation are introduced in this chapter. Then the direct method for hyperbolic heat transfer equation is derived. The simi-analytical method for sensitivity analysis is presented. The results of the example show the high precision of the algorithms.In chapter 5, the design optimization algorithm is developed for thermal shock problems.In the beginning, the mathematical model of design optimization and the solution algorithm are presented. Then some numerical techniques are employed to assure the convergence of the Sequence Quadratic Programming Algorithm. Finally the numerical examples show the efficiency of the method in this paper.In chapter 6, the solution method based on the sensitivity analysis for parameter identification of inverse heat transfer problems is studied. First, the mathematic...