TAILIEUCHUNG - Crack analysis for some structures subjected to thermal and dynamic loads
The influence of the temperature, dynamic loads or position of the crack on fracture parameters for these structures are investigated. The given programs may be useful for estimating the failure of dams, tunnels or other structures. | Vietnam Journal of Mechanics, VAST, Vol. 30, No. 3 (2008), pp. 167 – 178 CRACK ANALYSIS FOR SOME STRUCTURES SUBJECTED TO THERMAL AND DYNAMIC LOADS Ngo Huong Nhu Institute of Mechanics, VAST, 264 Doi can, Hanoi, Vietnam Abstract. Numerical methods of crack analysis for some 2D-elasticity problems with thermal and dynamic loads are considered in this work. The general steps of the algorithm are presented. Some programs are written by Gibian languages in the codes Castem for crack analysis of different structures. Numerical illustrations are realized for the crack dam model, the plate with one and two cracks the plate with crack at the hole subjected to under variable tension of thermal loads . The influence of the temperature, dynamic loads or position of the crack on fracture parameters for these structures are investigated. The given programs may be useful for estimating the failure of dams, tunnels or other structures. 1. FINITE FORMULATION OF CRACK ANALYSIS FOR STRUCTURES SUBJECTED TO THERMAL, DYNAMIC LOADS The main steps of crack analysis for some plates subjected to static load are presented in [1]. This part deals with the basis of solution for the problems with thermal and dynamic loads. . Thermal conduction problem Thermal effect within an elastic solid produces heat transfer by conduction and this flow of thermal energy establishes a temperature field in material. The equilibrium equation of heat flux in steady-state heat conduction has form [2]: Z Z Z X 0T 0 S B Θ kΘ dV = V Θq dV + Θ q S dS + Qi , (1) S i Θ kx 0 0 i , k = 0 ky 0 ; kx , ky , kz are anisotropy conductivity 0 0 kz coefficients, Θ is a temperature function, Θ expresses variation of Θ and it is virtual value. q B represents the ( heat) flux per unit of volume, q s is the (heat) flux per unit of surface and Qi are the heat, which is concentrated at the nodes. This equation represents that the quantities of ingoing and outgoing heat flux are equal. Note that(1) is similar as the
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