The Dynamic Response Of The Complex Structure Of The Technology And Applications Of Finite Element Analysis

Self-propelled howitzer is a complex structure. The launch process comprises high transient, heavy load and strong nonlinear, leading to serious impact and vibration. As the battlefield environment changes, self-propelled howitzer must be redesigned to meet the urgent requirement of lightweight. Therefore, the finite element modeling, considering various nonlinear factors, must be used to study the dynamic behavior of launch process, to obtain accurate prediction results of howitzer test.Based on dynamic fern modeling methods and techniques, system modeling method of complex structure is established. It covers two levels:component modeling and components connection modeling. The useful modeling techniques are studied in detail to control calculation scale and simulate nonlinear factors. Then the dynamic analysis methods, and the measures to improve solution efficiency, accuracy and stability are discussed.With system modeling method, the launch dynamic FEM of self-propelled howitzer was established. Based on the techniques of the large sliding contact, the user interface program, multi-point constraints and connectors, the characteristic of reverse recoil device and tracked suspension system was correctly simulated. And structure dynamic response of self-propelled howitzer was calculated, during fire, at the direction angle 0°and elevation angles 0°and 60°. The results compared with the test results, the maximum error was 5.1%, reached the requirement of analysis. Thus, research platform for launch dynamic FEM of self-propelled howitzer was established. On this basis, the effect of design and redesign of howitzer can be assessed. And the problems, such as structure optimization, lightweight and matching between howitzer and chassis, can be further studied.To solve practical problems with dynamic FEM rightly, depends on both correctness of modeling method and accuracy of model parameters. Some parameters, such as stiffness and gap, are difficult to measure. So parameter identification method is proposed. It's based on mathematical experiment. From the response output, the indicators, which are sensitive to parameters, are extracted. With the indicators, the physical model parameters can be measure indirectly. To identify the gaps and stiffness parameter, the indexes of kurtosis coefficients and standard deviation, were obtained through wavelet transform of dynamic response. With these identification indexes, parameters identification can be completed smoothly.