鈹中含氧化鈹夾雜相的殘余應(yīng)力數(shù)值模擬.pdf

1、寧夏大學(xué)碩士學(xué)位論文鈹中含氧化鈹夾雜相的殘余應(yīng)力數(shù)值模擬姓名：毛靜申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：固體力學(xué)指導(dǎo)教師：何力軍2011-03IIIAbstract As a low atomic number of structural material, beryllium which was widely used in nuclear energy, aerospace and other areas has remarkable compr

2、ehensive physical, thermal and mechanical properties .Especially in the development of nuclear energy, the consumption of beryllium has increased day by day. Beryllium prepared by powder metallurgy is brittle and reactiv

3、e metal. The method unavoidably introduces beryllium-oxide particles which cause embrittlening of beryllium and has a great influence on the mechanical properties of Be. In recent 20 years, to resolve the problem of brit

4、tle about Be is our mainly objective. It is well known that the thermal expansion coefficient between Be and BeO is different. In the paper, thermal residual stresses due to thermal expansion mismatch of BeO particles in

5、 high Beryllium were studied by FEM simulation. Thermal residual stresses have effect on mechanical property, yield strength, tensile strength, plasticity, toughness of composite material. Some domestic and overseas sch

6、olars studied residual stresses from welding and machining, little considering residual stresses field due to BeO introduced. In the simulations, supposing a period distribution of the BeO particles in the high Beryllium

7、, the matrix are modeled as elastic and elastic–plastic material The BeO particle is modeled as isotropic and linear elastic. All simulations were performed using the ANSYS finite element code. The main contents are as f

8、ollows： (1) Created a single-particle FEM model, by using the two kinds of finite-element method about elastic and elastic-plastic, the stress distributions were simulated using ANSYS software. The results show that us

9、ing elastic-plastic finite-element method is reasonable ； The effects of temperature-dependent materials properties were discussed on the relaxation mechanisms of the residual stress fields during cooling process.

10、 (2) The effects of particle volume fraction, shape and size were discussed on the relaxation mechanisms of the residual stress fields during cooling process. (3) Created multiple-particle FEM model, considera

11、tion on the BeO particles contained in Be gain and BeO particles distributed in the gain boundaries, simulations of thermal residual stresses distribution were performed using the ANSYS finite element code for the above

12、situation. The results show that considering BeO particles distributed in the gain boundaries will be given greater responsibility for fracture. The results of the study are of reference and guiding significance to the