夹具材质和摩擦对放射性圆柱样品变形及应力的影响

Influence of Material and Frictional Factor on Deformation and Stress on Radioactive Cylinder Sample Fixture

对放射性样品开展几何测量时,夹具与样品间的相互作用会导致样品变形不均匀,从而影响测试精度。采用有限元方法(FEM)研究了夹具材质及夹具-样品间摩擦因数对样品受力及变形的影响,研究表明:夹具材料与样品的弹性模量差异会导致样品的不均匀变形,较软样品的测试夹具应采用弹性模量较低的材料;应考虑样品的表面粗糙度对摩擦因数的影响,当摩擦因数大于0.4时,摩擦因数变化对样品的变形影响可以忽略。研究结果可为放射性圆柱样品测试夹具的优化及实验开展提供借鉴。

The interaction between the fixture and the sample during the geometric measurement of radioactive sample will lead to uneven deformation of the sample,and affect the test accuracy.The Finite Element Method(FEM)is used to study the influence of fixture material and friction coefficient between fixture and sample on the force and deformation of the sample.The study shows that the difference of elastic modulus between the fixture and sample material will lead to uneven deformation of the sample,and the test fixture for softer samples should be made of materials with lower elastic modulus.The influence of the surface roughness of the sample on the friction coefficient should be considered.When the friction coefficient is greater than 0.4,the influence of the change of the friction coefficient on the deformation of the sample can be ignored.The research results can provide reference for the optimization of the test fixture and experiment of radioactive cylindrical samples.