Flange Linear Motion Bearing,Linear Sliding Guide Block Bearing,THK Linear Bearing Ruihode Bearing Co., Ltd. , http://www.sdrollerbearing.com
For the unsteady temperature field problem, not only the temperature field changes with time, but also the deformation of the elastic body changes with time. Therefore, the influence of the acceleration term must be considered in the equilibrium equation. Meanwhile, the traditional Fourier derivative equation (1) is the micro-element Treated as a rigid body, but in fact, under the action of heat and force load, the strain of the micro-body changes with time, and the temperature field distribution of the elastic body is not only related to the heat absorption due to the mutual transformation of deformation and heat. And related to deformation.
Considering the heat conduction equation of the thermoelastic object micro-body deformation, it is called the modified Fourier heat formula, ie K$2T=CE9T9t T0B9e9t (2) where: CE is the constant volume specific heat of the elastomer, T0 is the initial temperature, B For the thermal stress coefficient, e is the volumetric strain.
Comparing equation (2) with equation (1), the second term on the right side of the equal sign is an additional term caused by the deformation. That is to say, the heat given to the elastomer not only causes a temperature rise, but also a part of the deformation work. This additional term is called the coupling term of the temperature field and the strain field.
It can be seen from equation (2) that the equation contains three displacement components and one temperature quantity with a total of four independent variables, so it cannot be solved independently. It is necessary to formulate three equations of equation (2) and equilibrium equation (displacement equation). The joint can solve. Because of this type of problem, the temperature field and the strain field interact to form a coupling relationship, so it is called a coupled thermoelastic problem.
Solving the thermal stress in the elastomer requires calculating the temperature and stress fields of the elastomer. At present, the methods for solving such problems include the finite element method [4], the boundary element method [5], and the perturbation method [6]. A commonly used and proven method is the finite element method.
In this paper, the finite element method is used to realize the thermoelastic coupling analysis by indirect coupling method in the finite element analysis software AN-SYS. Firstly, the thermal boundary condition is applied to the thermal analysis finite element model to obtain the temperature field of the gear. Then the thermal analysis model is converted into a structural analysis model. In the structural analysis, the obtained node temperatures are applied to the gears as body loads. Coupling calculation.
Boundary conditions: The thermal boundary conditions of the gear temperature field include the temperature of the solid surface, the convective heat transfer coefficient of the gear surface immersed in the lubricating oil, and the heat flux density on the gear meshing surface. Since the convective heat transfer coefficient and the heat flow density cannot be applied to one surface at the same time, the surface effect unit surf 152 is covered on the meshing surface, and the convective heat transfer coefficient is indirectly applied to the meshing surface.