Light Artillery Aircraft Design Optimization,

This thesis is mainly focused on weight reducing of D30 122 howitzer's trail. Two new structural forms of the trail body are explored, then structure optimal design for the minimum weight is carried out. Finally, a remarkable effect of weight reducing is obtained on condition that the qualification of strength and stability of the trail is satisfied.The main research are as follows: ①Stress and reaction force given by the ground of the D30 122 howitzer's trail are obtained by finite element software I-DEAS. A linear static and a linear buckling analysis of the right trail body are carried out by I—DEAS. The numerical value of stress and buckling factor of the right trail obtained here is used as a reference of performance constraint for the optimal design of the new trail body. ②Two new structural form of the trail body are designed. Finite element model is created through coupling shell element and beam element by the software MSC.PATRAN. Finally, parametric model of the structure is created by PCL (the secondary development language of PATRAN) programming in the environment of MSC.PATRAN. ③MSC.PATRAN and MSC.NASTRAN are integrated into iSIGHT optimization software. Applications of file parse, parameters table, design of experiments (DOE), optimization plan in iSIGHT are studied. ④A combination strategy of DOE plan and optimization plan are used for structural optimization of the two new structural forms of trail body in the optimization software iSIGHT. Orthogonal Arrays method is used in DOE plan, while Multi—Island Genetic Algorithm is used in optimization plan.This thesis applies optimization software iSIGHT to integrate with finite element analysis software. Based on parametric model and Multi—Island Genetic Algorithm which is a exploratory technique in search of the global optimum, size and shape optimization of a typical component of artillery has been carried out.