平面应力状态下混凝土的热弹塑性积分方案

Integration Strategy for Thermal-Elastic-Plastic Models of Concrete under Plane Stress

在高温状态下的屈服函数是温度和塑性应变的函数,塑性应变不仅与应力状态有关,还取决于温度。如果采用常规的计算方法,如径向返回法,需要更多的迭代运算,造成计算效率不高。另外,对于单轴受力情况,每个时间步内的温度路径也是很难确定。采用平面应力状态下混凝土常用的屈服函数Drucker-Prager准则,给出了相应的高温热弹塑性积分方案的初值问题表达式,可采用Runge-Kutta法对其积分,较好地解决了前面两个问题。采用基于S-R分解原理的更新拖带坐标有限元法,通过实际编程计算得出,该积分方案可靠、精度高。

Plastic strain was determined at multiple time increments.The strain was caused by stress and temperature.The yield function in high-temperature states is the function of temperature and plastic strain.The calculation efficiency would be decreased and much more calculation would be needed if a conventional method,such as the radial return method,was used.In the case of axial stress states,the temperature path was difficult to determine at various time intervals.Initial value equations were obtained with the...