在ANSYS中开发用响应面法求解结构可靠度的专用程序

ANSYS用于对结构作概率分析,可求得复杂结构的可靠度.但ANSYS采用的随机变量分布类型中无极值型分布,而工程结构所承受的实际载荷大多为极值型分布.为处理此类情形,该文用ANSYS自带的二次开发工具APDL语言开发了用响应面法求解结构可靠度的专用程序.与ANSYS的另一开发工具UPDFs相比,文中开发的程序完全独立于ANSYS核心程序,不用对其修改,不会影响其稳定性,故适用范围更广.为了方便使用,文中用VB程序编制了输入随机变量的类型及控制参数的交互界面,并自动生成可用于ANSYS以Batch mode方式运行所需的控制文件.对于计算中各随机变量相应设计点的变动过程,特别是非正态变量在验算点处的当量正态化,用AutoCAD中Visual LISP语言编制了相应的显示程序,部分实现了计算过程的可视化.

Development of special program to calculate structural reliability based on RSM in ANSYS

Probabilistic Design System(PDS) ANSYS can be used to do structural probabilistic analysis to obtain the reliability index of complex structures.But there is no Gumbel distribution in distribution types of random variables used in ANSYS,and the loading of practical engineering is almost of Gumbel distribution.To deal with this,a special program was developed with ANSYS Parametric Design Language(APDL) based on Response Surface Method(RSM) to calculate the structural reliability.Compared with another developing tool UPFs,the tool used in this paper(APDL) does not need to modify the core of ANSYS,so it will not affect the stability of ANSYS and can be used in wider range.For convenience,an interface was made by VB to input distribution type and governing parameter of random variables.And this VB program can automatically form the global controlling file,which can be executed under Batch mode in ANSYS.Utilizing Visual LISP in AutoCAD,a program was developed to illustrate the updating of design points,especially normalization of non-Gauss distributed random variables at checking points,so part of the iteration procedure can be visualized.