Research On Mechanical Environment Numerical Simulation And Reliability Design Of Launch Vehicle Electronic Equipment

As the size of the launch vehicle becomes larger and larger,the electrical system on the launch becomes more and more complex,the function becomes more and more important,and its reliability is more and more difficult to guarantee.The electrical system is mainly composed of various launch vehicle electronic equipment and cables.To ensure the high reliability of the electrical system,the reliability of the launch vehicle electronic equipment should be ensured first.Electronic equipment often contains many sophisticated electronic components.Under the action of mechanical environment such as vibration,shock and overload during launching and flight of the launch vehicle,the response of the electronic equipment is relatively severe,and the printed circuit board undergoes large dynamic bending deformation,which is one of the main causes of electronic equipment failure and even electrical system failure.There have been many quality problems caused by the failure of electronic equipment.Taking the quality problems that occurred in 2016 as an example,there were 253 quality problems in the whole year,of which 103 were electronic equipment quality problems,accounting for 40.7%.Judging from the quality problems that have been solved,electronic equipment failures are mainly caused by mechanical environment,thermal environment,electromagnetic compatibility,natural environment,among which the quality problem caused by the mechanical environment accounts for 20%.Therefore,the research on the numerical simulation and reliability design elements of the mechanical environment of the launch vehicle electronic equipment are of great significance to avoid the repeated design of the electronic equipment,improve the reliability of the electrical system,reduce the number of quality problems,and reduce the development cost.In this paper,the electronic equipment is taken as the research object.The dynamical response of the electronic equipment in the mechanical environment is calculated by finite element numerical simulation method.Then the modal test and vibration test are carried out,and the simulation results are compared and the accuracy of the finite element model is verified.Taking a printed circuit board with a regular shape as the object,the reliability design elements were studied from six aspects: absorber cushion,number of pins,component position,bracket addition,bolt mounting density and board thickness.The influence of each element on the mechanical environment of the printed circuit board provides reference for reliability design and material selection in the project.Finally,based on the interaction between MATLAB and NASTRAN software,the intelligent optimization algorithm is used to optimize the component layout and screw layout,and achieve global optimization for the purpose of reducing component pin position acceleration,which is optimized for reliability in engineering.It provides a feasible method to improve the reliability of products.Through the above research work,the numerical simulation process,method and reliability design elements of the launch vehicle electronic equipment for practical application of the project have been formed,and the expected research objectives have been achieved.