固体推进剂复合加载夹具及试件的设计与分析

Design and Analysis of Combined Loading Fixture and Specimen for Solid Propellant

为研究固体推进剂在拉剪复合载荷作用下的力学性能,满足实验加载需求,设计了适用于固体推进剂复合加载的实验夹具及试件。应用Abaqus有限元分析软件对试件在复合加载过程中的应力应变进行了仿真计算。基于拉剪加载解析理论,对试件的变形进行了理论分析。结果表明:在拉剪复合载荷下,直线-圆弧型蝶形试件的应力集中范围较小,其对称线上存在8mm长度的剪切应变均匀区域;蝶形试件V形开口处过渡圆角的增大会导致应力集中影响范围增大,导致试件最大应力与中心点应力的差值减小;蝶形试件的真实拉伸应变和剪切变形的理论值与仿真值相对误差在5%之内。得出结论:所设计的夹具可有效实现固体推进剂的拉伸、剪切和拉剪复合加载,拉剪应变解耦方法能较好的计算出试件的真实应变。

In order to study the mechanical properties of the solid propellant under the combined load of tension and shear,to meet the experimental loading requirements,an experimental fixture and specimen suitable for the composite loading of solid propellant were designed.By using the Abaqus finite element analysis software,the stress and displacement of specimens under the combined load in the test section was simulated.Based on the analytical theory of tensile-shear loading,the deformation of the specimen was analyzed theoretically.The results show that the stress concentration range of the straight-circular butterfly specimen is smaller under the tension-shear load,and there is a uniform shear strain region of 8 mm in length on its symmetry line;the increase of the transition fillet at the butterfly specimen V-shaped opening will increase the influence range of stress concentration,and the difference between the maximum stress of the specimen and the stress at the center point will decrease.The relative error between the theoretical and simulated values of the true tensile strain and shear deformation of the butterfly specimen is within 5%.It is concluded that the designed fixture can effectively realize the composite loading of the solid propellant under tensile,shear and tensile-shear load,and the true strain of the specimen can be well calculated by the tensile-shear strain decoupling method.