Method for determination of uniaxial constitutive relation of materials for radial compression energy prediction of circular rings

Abstract

The invention discloses a method for measuring the uniaxial constitutive relationship of a circular ring radial compression energy prediction material. A compression fixture with a limit groove is used to carry out quasi-static compression loading on a variable-sized circular ring to obtain a continuous load P After the ‑displacement V curve, the radial compressive stiffness S of the ring is calibrated by the data of the elastic segment of the load‑displacement curve, and the uniaxial constitutive relationship of the material is predicted after post-processing. The invention overcomes the disadvantages of the prior art that multiple finite element iterations are time-consuming and labor-intensive, and the advantages and disadvantages of the convergence cannot be evaluated in advance. In particular, it is of great significance to obtain the uniaxial mechanical properties of materials for important pipeline structures that widely exist in key projects such as aerospace, nuclear power, high-speed rail, and oil and gas transportation.

Description

technical field [0001] The invention relates to the technical field of material mechanics experiment equipment. Background technique [0002] The uniaxial stress-strain curve (that is, the constitutive relationship) is the key link to establish the relationship between materials and mechanics, and plays an important role in the design and service of engineering components. The usual way to obtain the uniaxial constitutive relation of materials is to conduct tensile tests in the laboratory after processing raw materials or cutting standard tensile specimens from engineering components. With the development of structure miniaturization, limited by the size of components, it is difficult to obtain effective sample expansion tests according to traditional sampling methods. However, for key engineering pipeline structures such as aviation and nuclear power (such as nuclear fuel cladding tubes), it is difficult to intercept standard specimens, which makes the traditional tensile ...

AI Technical Summary

Problems solved by technology

Obviously, this method does not consider the influence of the error of the empirical formula of yield load on the results, and the process of multiple iterative calculations is cumbersome, which is not conducive to the easy acquisition of the uniaxial constitutive relationship of tubular materials or structures

In addition, the approximate formula of this method requires that the length l of the round tube is greater than its diameter D to be effective, so there is still a certain amount of material waste in the length direction

[0013] In the existing technical solution 2, multiple finite element iterative calculations are also required, which is time-consuming and laborious

And the convergence of the iterative result is greatly affected by the given initial value, and there is a problem that the convergence cannot be evaluated in advance

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