DescriptionSensitivity analysis of total strain energy for nonlinear structures is studied. Based on the law of energy-consistent, the effective strain and stress have been defined to provide scalar measures of the strain and stress for the two and three dimensional problems. The total strain energy is transformed in the form of the effective stain and stress. A closed-form approach for sensitivity calculation is derived. This method can also be extended to large displacement, large rotation problems using the 2nd Piola-Kirchhoff stress and Green-Langrange stress.
The numerical examples with both geometric and material nonlinearity are presented to demonstrate the applications for the proposed sensitivity analysis calculation for strain energy. To evaluate the accuracy of the new method, numerical results obtained by the proposed method are compared with those from both analytical solution (for simple geometry) and finite differencing method.
The closed-form solution of design sensitivity is also applied for reliability-based structural design. Specifically, the case study is performed for the problem for the uncertain applied force performed, and uncertain Young's modulus with nonlinear materials. The numerical results obtained by the close-formed solution are compared with those from Monte Carlo simulation.