3-DIMENSIONAL DESIGN SENSITIVITY ANALYSIS USING A BOUNDARY INTEGRAL APPROACH

A general shape design sensitivity analysis approach, different from t raditional sensitivity methods is developed for three-dimensional elas tostatic problems. The boundary integral design sensitivity formulatio n is given in order to obtain traction, displacement and equivalent st ress sensitivities which are required for design optimization. Those i ntegral equations are derived analytically by differentiation with res pect to the normal to the surface at design variable points. Subdivisi on of boundary elements into sub-elements and rigid body translation m ethods are employed to deal with singularities that occur during the n umerical discretization of the domain. Four different examples are dem onstrated to show the accuracy of the method. The boundary integral se nsitivity results are compared with the finite difference sensitivity results. Excellent agreement is achieved between the two methods.