Mechanical Analysis And Structural Optimization Of Light Lattice Sandwich Structure

With the development of material manufacturing and forming technology, latticesandwich structures are developed rapidly in recent years. As a new kind ofmultifunctional materials, lattice sandwich structures have been receiving increasingattention because of their excellent mechanical properties, such as ultra light, highspecific strength, high specific rigidity, extremely high absorption of energy, as well asother additional special properties, such as shock absorption, heat dissipation, soundabsorption and electromagnetic shielding, etc.In order to use efficiently the excellent thermal-mechanical properties of latticesandwich structures, structure optimization of three typical sandwich structures-tetrahedron, pyramid and truss type panel, are performed with an aim of minimizing theweight. Meanwhile, a genetic algorithm method for structure optimization is given, withwhich the optimization solutions are obtained and compared with the existing solutions,demonstrating the validity of the application of the genetic algorithm method in theoptimization of the structures.There are six chapters in this thesis, and the main content is briefly stated asfollows:In the first chapter, the background and progress of lattice sandwich structures areintroduced, including of the concept, origin, development and manufacturing methodsof lattice sandwich structures, as well as some research status home and abroad. Thegenetic algorithm structure optimization method is put forward.In the second chapter, detail information on the genetic algorithm for structureoptimization is introduced, from which the characteristics of the genetic algorithm aresummarized. Then, several methods dealing with the commonly used constraints arebriefly introduced.In the third chapter, the stiffness of three kinds of lattice sandwich structures withfiber-reinforced composite veneers is analyzed with analytical approach, and compareswith the results obtained with finite element method.In the fourth chapter, the genetic algorithm is applied to the optimization of threetypical sandwich structures, and the results obtained are compared with the existingresults.In the fifth chapter, a general analysis of the dynamic property of a pyramid lattice sandwich structure is obtained and is used to calculate the natural frequencies of thefour-side simple support pyramid lattice sandwich structure in the first four phrases andthen compared with that of the solid panels with the same mass.In the sixth chapter, the conclusion of the research on this thesis and the futurepossible research aspects are suggested.