考虑材料性质参数随温度变化的热屈曲试探解法

Trial and error method of thermal buckling for complex structures

分析了结构热屈曲问题的非线性性质，提出了考虑材料性质参数随温度变化的热屈曲试探解法，在ＤＤＪＴＪＱ程序上实现了材料参数（弹性模量Ｅ、泊桑比μ、线膨胀系数α）随温度变化情况下复杂结构热屈曲有限元数值分析．数值计算结果表明，由于温升所产生的热应力和材料的力学性质的软化，将使结构的屈曲强度大大降低．原先处于正常工作状态的工程结构，在又受到温度载荷作用后，有可能发生灾难性的屈曲破坏．

The material physical properties, such as Youngs modulus, Poissons ratio and coefficient of thermal expansion, are changing with the temperature in the structures, so that the thermal buckling behaviour is actually non linear in the temperature. The trial and error procedure is presented for thermal buckling of the complex structures in this paper. A corresponding computer program by using finite element method is coded in FORTRAN 77 and is implemented on microcomputers. Numerical results show that the thermal stress and material softening will induce the catastrophic buckling failure of the pre compressed structures.