Research On The Max Entropy Structure Optimization Algorithm Based On Parameters Self Adjustment

Focused on the Max Entropy principle of information theory, a new kind of structural optimization method based on parameter self adjustment is systemically studied in this dissertation.In this thesis, the main achievements of research are as follows:The application of max entropy in structural optimization is fully described. In the aspect of max entropy theory, the most up-to-date research and achievements in structure optimization of those scholars with the representative of Professor Li Xing Si is introduced; with optimization of discrete variable, the method of attached constrain bring forward by HuoDa is described. Those innovative achievements form the base and back ground of this dissertation.By studying the selection of slack parameter from the viewpoint of iteration condition, a method, named MEMP, with main character of self adjustment based on traditional entropy principle is given. Instead of debugging with experience frequently in the calculation of parameters, this method , different from the traditional parameter selection meihod by manual adjustment, lirstly distinguish the good from the bad condition of iteration, and then take a few self adjustment steps with the corresponding iteration status.In the level of first order, the inference of traditional truss size optimization model from the standpoint of Taylor approximation is given. Without the traditional assumption of static determinacy, this thesis prove first order precision of the model with reciprocal substitution in truss optimization.With the simplified formality of K-S coherence function, the conception of proxy is broadened by substituting K-S function with proxy objective assessment function given in this thesis. In addition, a new kind of proxy method named MOP based on proxy objective function is also given.With the combination of algorithm MEMP and MOP given by this dissertation, the shape optimization model of truss structure is researched and a kind of two-steps optimization algorithm based on max entropy is presented .The shape optimization problem of truss structure is been divided by this method into two stages: area stage and coordinate stage, with its corresponding algorithm named MEMP and MOP. In the view of max entropy principle, this method can be viewed as the model of comprehensive application.The method of attached constrain is studied. By extending the discrete variable condition with continuous real smooth constrain function, further study is been carried out in truss size optimization model. In addition, the method is popularized in other optimization such as those optimization models with mixture variable of continuous type and discrete type.In the last part, the summarization of this dissertation is given with the suggestion of further research on some remaining problem.