Abstract
Evolutionary Structural Optimization (ESO) method is one of the powerful and promising techniques for pursuing the optimal structural form. Although it is easy to carry out the calculation of ESO, there have been remained some weak points in its evolutionary process, by which inefficiency of calculation is caused or unreasonable solutions are generated. A new method through the usage of the contour lines is proposed in order to remove such defects of the usual ESO as well as to enable the structures to not only be scraped off but also grow up toward the final optimal structures. Some numerical examples clearly show the effectiveness of the proposed scheme.