Structural Dynamic Design And Analysis Of Signal Transform Device

The signal transform device is an important states measuring and signal transforming facility in the flight experiments. In structure, it is an aluminum case that contains a printed circuit board with various attached electronic components such as capacitors, resistors, relays, and integrated circuits. Some relays on the printed circuit board were destroyed under random acceleration excitations. In order to improve the product reliability, the new signal transform device must be designed.Vibration can cause damage to products by abrasion, fatique and overstress and may contribute to early product failure during use. Almost every type of machinery undergoes some type of random vibration, and it is the job of the analyst to determine if the system can stand up to this loading. Dynamic loading plays a critical role in the functional performance and mechanical reliability of microelectronic components and devices. For the signal transform device, a commonly met dynamic loading is random vibration, as met in the flight experiments, etc. Therefore, analyzing the dynamic response of some key components under random vibration , and further minimizing its adverse consequences on the products is very important for the signal transform device designs. The method of dynamic design for the signal transform device based on the virtual environment is studied in the paper. The dynamic design and capability analysis for the structure can be carried out in the virtual environment, and the weakness of design can be found in time. The finite element method has been widely applied in the fields of research, construction and design and has become anecessary tool to solve complicated problems in engineering practice. Finite element method is still under development and improvement. It will be exciting for finite element analysis in future years.This study introduces the author's research and engineering working on structural dynamic design. At first the method for calculating the fundamental natural frequency of structure is researched. There may be hundreds of potential vibration modes in a typical structure, but usually, it is only a small number of vibration modes with the lowest frequencies that are of interest. The general concept and principle of finite element method is discussed. With the advancement of finite element analysis (FFA) modeling, model-based design of mechanical structures in general is replacing the traditional trial-and-error approach. Computer-aided design (CAD), together with Computer-aided engineering (CAE), is already regarded as an effective tool for the generation modification, analysis, simulation, and evaluation of a product design. The FEA model of the signal transform device is established with the use of ANSYS based on design specifications and tests. The fundamental natural frequency predicted by the FEA model is consistent with it obtained by the tests. The spectrum analysis of random vibration response is deeply researched. Response spectrum analysis (RSA) is a procedure for computing the statistical maximum response of a structure to a base excitation (or earthquake). Each of the vibration modes that are considered may be assumed to respond independently as a single-degree-of-freedom system. Having determined the response of each vibration mode to the excitation, it is necessary to obtain the response of the structure by combining the effects of each vibration mode. The maximum response depends on the natural frequency of the single-degree-freedom system and the damping ratio of the system. One of the most important types of mechanical simulation is the prediction of a system's behavior due to random vibration. Finally, the random vibration analysis of the signal transform device is presented. Experimental modal analysis is discussed briefly. The reasons why the relays on the printed circuit board were destroyed under random acceleration excitations are found out. The modifying technique of structure dynamic model is also introduced.On the bases of structural dynamic analysis, a new...