论文部分内容阅读
一、引言 在求解各种定解问题时,化偏微分方程为积分方程是一个比较复杂的过程,归化的途径多种多样,可以从同一边值问题得到几个不同形的边界积分方程,对于各种方程及其定解问题没有统一的方法。C.B.Brebbia提出了用加权余量格式建立有关的边界积分方程的直接法。在变分法中,可以用拉格朗日乘子引入约束条件,用内积构造泛函,通过变分建立各种广义变分原理,这些拉格朗日乘子是可以识别的。类似于变分法,也可以通过加权余
I. INTRODUCTION When solving a variety of definite solution problems, it is a complicated process to convert the partial differential equation into an integral equation. There are many ways of naturalization, and several different types of boundary integral equations can be obtained from the same boundary value problem. There is no uniform method for the various equations and their definite solutions. C.B. Brebbia proposed a direct method for establishing the relevant boundary integral equations using the weighted residual format. In the variational method, Lagrange multipliers can be used to introduce constraints, and inner products can be used to construct functionals. Variational principles can be used to establish various generalized variational principles. These Lagrangian multipliers can be identified. Similar to the variational method, weighted residuals can also be used