阻尼溶剂抽取法中关键因素取值优化模型

Optimization of the key factors in the damping solvent extraction method

阻尼溶剂抽取法中关键因素包括人工阻尼系数和有限区域尺寸等,对结构-地基相互作用的分析计算有很大的影响。为消除关键因素取值随机性对计算结果的影响、有效控制交界面相互作用计算结果的精确度和计算效率,分析了弹性地基上杆件在不同状态下无量纲动力刚度系数间的相互关系,构建了关键因素取值优化模型。无量纲有限区域大小与人工阻尼系数的函数关系式定义为目标函数,无阻尼无限杆近似计算与解析计算的动力刚度系数差值函数定义为约束条件。已知偏移允许最大值和节点振动幅值衰减目标值,解得无阻尼无限杆近似计算动力刚度系数中关键因素的最优取值。数值算例验证了关键因素取值优化模型及求解方法是合理可行的,能够有效控制模拟计算的精确度和计算效率,亦验证了该模型的工程适用性。

The key factors of the damping solvent extraction method are artificial damping coefficient and size of unbounded medium. The solutions of the key factors have great influences on the accuracy and the efficiency of the dynamic simulation of the interaction of structure-foundation. To avoid the randomness and uncertainty of the key factors, the value optimization model of the key factors is established in this study. The corresponding objective function is the relationship between the size of un bounded medium and artificial damping coefficient. The constraint condition is the difference function of dynamic stiffness coef ficient between the simulating solutions and the analytical solutions of the undamped unbounded rod. Since the maximum of dynamic stiffness coefficient and the attenuation values of node vibration amplitude of undamped unbounded rod are known, the key factors can solve the optimal solution. The undamped unbounded rod on the elastic half-foundation and the semi-infinite rectangular foundation are applied to validate the feasibility of optimization model of the key factors.