Theoretical Research And Numerical Simulation On The Measurement Of Material Mechanical Performance Based On Annular Specimen

With the rapid development of material science,a number of new materials appear rapidly,such as fiber reinforced composites,surface coating materials,functionally graded materials and so on,and are widely used in the aviation,aerospace,power,shipping and petroleum fields.The variety of materials and processing technology,result in a large difference in the characteristics of the material.In order to give a full play to the function of new the materials,the material performance test and structural test have become the key to the application of the material and structure design.However,in the field of new material mechanical properties,there is no mature evaluation standard and test method so far.It is urgently needed to improve the existing methods and equipments of mechanical performance measurement to meet the demands in experiments and engineering.In this paper,a new experimental theory is established based on annular specimen and radial loading to overcome the shortcomings of the traditional test.It is only needed to measure the radial displacement of the annular specimens in the new experimental method and we can get all material constants of isotropic or orthotropic material,especially the transverse elastic modulus perpendicular to the fiber direction which is impossible to the conventional testing method.Through the effect analysis of measurement errors to test results,it is proved that the new theory is very practical.The new test method can become very accurate by using advanced measurement technology to reduce the measurement error.Meanwhile,in the process of loading mechanism design,the loading mode,loading range and the size of the loading block are analyzed in detail,the influence of the displacement error to the result are further reduced.The material constants are calculated by replacing the uniform displacement with the average value and replacing the uniform pressure with the measured pressure value,the difficulty of data observation in the testing process can reduced effectively,which can improves the practicability and economy of the test method.The method can be used to simulate the internal pressure of varies pipelines and to check different tubular products,which will reduce the inspection cycle and the testing costs greatly.The study has a great practical significance to enhance the level of mechanical properties measurement and tubular structure test.