Then its generalizedvariational principle is established on the basis of Lagrange multiplier method by absorbing the first kind of boundary condition.
然后利用拉格朗日乘子法，吸收第一类边界条件，从而得出其广义变分原理；
2
The derivation of generalizedvariational principles with preconditions by the use of the Lagrange multiplier method.
应用拉氏乘子法推导有先决条件的广义变分原理。
3
A calculation method is proposed to determine the crack tip stress intensity factors for sections on the basis of zonal generalizedvariational principles.