Design And Research On Dynamic Strength Of Large Caliber Artillery

Structure strength of large caliber howitzer during launching is a key research projects in lightweight design of howitzer. With the development of computing technology and finite element method. Research on structure strength of howitzer under impacting loading has a new technical way.Design and research of dynamic strength on a large caliber lightweight towed howitzer and vehicle mounted howitzer ’structure is presented in the thesis. Based on structure dynamic nonlinear finite element theory. Structure dynamic analysis was made on the preliminarily determined of overall structural layout and parameters for howitzers. Structural dynamics modification and structure dynamic response optimum matching design of howitzers were also studied. The key work of the theis includes:(1) The current situation of large caliber lightweight howitzer, nonlinear finite element method and dynamic strength design of structure were summarized. Finite element modeling technology of the complex structures system was studied. Finite element Numerical method of nonlinear structural dynamics was expounded. These establish a firm theoretical basis for complex structure dynamic nonlinear finite element modeling and analysis.(2) A nonlinear structural rigid-flexible coupling dynamics finite element model of the lightweight towed howitzer was formulated. The dynamic contact process between bottom carriages, rare carriage and pins was simulated. Dynamic stresses distribute law of bottom carriages, rare carriage and pins under four firing conditions of the lightweight towed howitzer were obtained through the calculation. It’s convenient and accurate to obtain dynamic contact stress of the hole edge of bottom carriages and rare carriage, which is difficult to measurement in the practical engineering firing test.(3) A nonlinear dynamic finite element model of vehicle mounted howitzer was formulated. The related force, motion characteristics and dynamic stress of structure for a vehicle mounted howitzer were obtained through the calculation. Conclusions of numerical value calculation offer a technological support for overall structural layout plan determination, parameters selection of structure in key position, selecting material of the vehicle mounted howitzer.(4) Bottlenecks in strength design of bottom carriage for a lightweight towed howitzer and frame for a vehicle mounted howitzer were found by using nonlinear dynamic finite element analysis. Improved design of partial structure of bottom carriage and frame were presented, Structural dynamics model modification calculation show that the maximum stress of modified structure are decreased significantly and the modification project is feasible(5) Research on the influence law of structural strength of a vehicle mounted howitzer affected by the equivalent stiffness of hydraulic component. Aiming at the problem that response mutual conflict between top carriage stress and cylinder force of trails, structural dynamic response optimum matching design of howitzer was studied based on the Pareto optimality concept. the research result has directive significance to the structure design scheme selection for the vehicle mounted howitzer.Design and research of dynamic strength on large caliber howitzer’s structure was presented in this thesis has important engineering value for guiding the structure design of a howitzer,Analysis approach and design methods has generality for dynamic strength design of other mechanical structure.