Tolerance Design And Numerical Simulation Of Cableless Aerospace Electronic Chassis

In recent years,the volume of aerospace electronic chassis has become more and more miniaturized,the chassis structure is more complicated,the internal components are more and more,and the heat flux density per unit volume is increasing.The traditional cable chassis has technical bottlenecks such as heavy weight,complicated structural design,and is not conducive to replacement.In response to these problems,this paper based on the three-dimensional CAD software SolidWorks and CAE software ANSYS workbench to carry out a cableless electronic chassis integration optimization design research.The specific research work is as follows:1.The miniaturized and integrated application of electronic components has gradually increased the heat flux density of the chassis in a unit volume,which puts high requirements on the heat dissipation performance of the chassis.This article is based on the Steady-State-Thermal of ANSYS workbench.The locking bar on the box is solidified into the working environment state,and the electronic equipment inside the module box is simplified into a unified heat source.Considering the heat flux density and component layout of the electronic equipment during actual operation,a temperature field analysis is performed on the cableless electronic chassis and will affect the electronic equipment.The heat source power for heat dissipation,the size and number of heat sinks in the cabinet,the position of the heat source,the heat source power,and the material properties were parameterized,and the overall temperature cloud map was obtained.The results show that the heat generated by the electronic device is transmitted to the locking bar through the module box and passes The contact between the locking strip and the heat sink on the inner wall of the chassis allows the heat to be conducted to the surrounding of the box and diffuse into the air,and the maximum temperature is within the rated temperature range of the electronic device to meet the thermal design requirements.2.In view of the wear and tear,fatigue damage and excessive plastic deformation of the connector caused by the connector during the insertion and removal of the module box,the static force of the ANSYS Workbench was used to discuss the friction force of 0.3 and the insertion angle of the module box.When the contact area of the module box and the slot on the motherboard assembly is deformed,the results show that the positioning pin of the module box and the positioning hole of the motherboard assembly are deformed the most,and the maximum equivalent stress in the insertion and removal area meets the yield strength requirements;The variable of the pulling force is parameterized.3.Aiming at the problems of most electronic chassis with complicated structure,many parts,and low efficiency of traditional manual calculation,the Computer Aided Tolerance(CAT)is integrated on the SolidWorks platform with the help of the secondary development function of SolidWorks.Using feature-feature size and assembly relationships,combined with SolidWorks API interface object model and secondary development language VB,human-machine interaction is used to mark dimensions and tolerances in the assembly environment.By traversing the assembly model,the size information is stored in the dictionary,and the size information related to the closed ring is stored in the structure array to form a complete and ordered loop.Based on the closed loop and loop search direction,the vector cosine method is used to determine the increase and decrease of the component loop,and the design function of the dimension chain is generated.Related research has realized the integrated design process of chassis "tolerance design-simulation analysis-product realization".The automatic generation of dimensional chain greatly improves the efficiency of tolerance analysis;the integration of the simulation process reduces the time cost of repeated modeling,and has certain practical value and theoretical reference for the design of aerospace cableless electronic chassis design.