Strain DIC Analysis Of Solar Cell Array In Operating Temperature Environment

As the energy source of the spacecraft,space solar array is one of the key components of a spacecraft.The service life of a solar array often determines the service life of a spacecraft.However,when the space solar array is working in space,it is prone to appear damage or destruction because of the complexity of the thermal environment.This kind of damage or destruction will result in reduction of the energy conversion efficiency or even failure of the whole array,which eventually lead to the paralysis of the spacecraft.Therefore,analyzing the thermal strain distribution of the space solar array’s multilayer structure under the complicated space thermal environment and revealing the failure mechanism of the solar array,which are the actual requirements of China’s navigation satellites,manned spaceflight,deep space exploration and other major special projects,have a great significance.The traditional method is difficult to test the full field thermal strain distribution of the surface and inter-layer of solar array’s complex multilayer structure.In this paper,based on the DIC(Digital Image Correlation)test method,a non-contact surface strain test system and a micro-interlayer strain test system were built to test the thermal strain distribution on the surface of the solar array substrate,the surface of the solar array battery and the thickness direction of the solar array module.Combined with finite element simulation analysis,the thermal strain distribution law of the solar array under a specific temperature field was obtained,which provides theoretical basis and experimental support for further revealing the failure mechanism of the solar array structure.The main research work is as follows:Firstly,This paper described the background and significance of the research.The basic structure of a space solar array was introduced,and the current status of domestic and foreign research on the thermodynamic analysis of solar arrays was investigated from the theoretical calculations and experimental methods.It was found that there are few reports on the thermal strain distribution of the solar array’s multilayer structure under an uneven temperature field.Digital image correlation test method was proposed to analyze the thermal strain distribution on the surface and thickness direction of the solar array.Secondly,this article introduced the basic principles of digital image correlation test methods,and explained the test system and experimental techniques of digital image correlation test methods.Two reference experiments were designed to verify the reliability and effectiveness of digital image correlation test methods at different strain levels.Thirdly,in this paper,simulated solar radiation,a temperature-loading system was designed to apply a temperature field which has a temperature difference between the upper and lower surfaces of the solar array.A non-contact surface strain test system and a micro-interlayer strain test system were built to test the thermal strain distribution on the surface of the solar array substrate,the surface of the solar array battery and the thickness direction of the solar array module.The thermal strain distribution law of the solar array was obtained,and the failure mode of the solar array’s multilayer structure was observed.Finally,this paper used ABAQUS finite element software to model the solar cell array.The temperature field of the solar array along the thickness direction was obtained by the heat transfer model;the thermal strain distribution on the substrate surface and the battery sheet surface was obtained by the three-dimensional finite element model and the inter-layer thermal strain distribution was obtained by simplifying the three-dimensional finite element model to the two dimensions model.The simulation results were consistent with the experimental results,which prove the validity of the digital image correlation test method for testing the thermal strain distribution of space solar arrays.