A Calculation Method of Contact Stiffness of Machine Tool-Foundation Interface Considering Concrete Asperity Breakage

Abstract

The invention discloses a machine tool-base joint surface contact stiffness calculation method in consideration of concrete asperity fracture. According to the method, a fracture phenomenon is thought to be generated when the asperity on the surface of the concrete suffers from large load, the originally-fractured asperity load is shouldered by other un-fractured asperities, fracture of an asperity continues to happen, and so on and so forth, a balance state is achieved. Firstly, according to a uniaxial pressure stress-strain curve of a corresponding concrete mark, the relationship between the concrete critical fracture stress and a critical fracture area of a single asperity is built, a critical deformation area value of the single asperity is acquired, and based on a fractal theory, the bearing forces of the concrete asperity in elasticity, plasticity and fracture deformation stages are solved respectively. A finite element method is adopted to extract the contact pressure of a sample joint surface under different pretightening forces, the concrete-steel joint surface contact stiffness is acquired and calculated on the basis, simulation analysis is carried out by using ANSYS, and an experiment is designed to verify a theoretical model.

Description

technical field [0001] The invention belongs to the field of machine tool dynamics, and relates to a method for calculating the contact stiffness of a machine tool-foundation interface considering the breaking of concrete asperities, and more specifically to a machine tool-foundation interface considering the load iteration of concrete asperities in different deformation stages Contact stiffness calculation method. Background technique [0002] In many industries, large-scale power machinery and heavy-duty machine tools are more and more widely used. Any fixed machine tool needs reliable support from the foundation. like figure 1 As shown, the foundation is usually made of concrete and is attached to the machine footing. Due to the characteristics of heavy-duty machine tools such as heavy weight and large load, the working accuracy and life of large-scale components such as the bed and columns are directly affected by the foundation and foundation, especially the load-bear...

AI Technical Summary

Problems solved by technology

In engineering practice, due to the lack of consideration of the interaction between heavy machine tools and foundations, it often occurs that the dimensional accuracy cannot be guaranteed.

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