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摘要:
为了得到波纹板的宏观刚度特性及其与表面形貌结构参数的关系,基于单胞有限元的方法对波纹板的等效刚度特性进行了研究。首先,基于单胞有限元的周期性边界条件,计算了具有周期性排布特点的波纹板的等效刚度;然后,计算了典型形貌波纹板的等效刚度特性,并进行了分析和验证;最后,运用单胞有限元的方法分析了波纹板结构参数对等效刚度特性的影响。分析结果表明:采用单胞有限元的方法可以有效计算波纹板的等效刚度;波纹板相较于基础薄板具有更高的弯曲刚度,但拉伸刚度和剪切刚度较低。当基础薄板厚度固定时,随着波纹板相对厚度的增加,拉伸刚度和剪切刚度降低,弯曲刚度升高;随着波纹板波纹相对周期间距的增加,拉伸刚度和剪切刚度升高,弯曲刚度降低。
Abstract:To obtain the macroscopic stiffness property of the dimpled sheet and its relationship with surface morphology structure parameters, the unit cell finite element method finite element method was used to analyze the equivalent stiffness property of the dimpled sheet. Firstly, based on the periodic boundary conditions of unit cell finite element method, the equivalent stiffness of the dimpled sheet with periodic check board pattern was calculated. And then the equivalent stiffness of a specific dimpled sheet was analyzed and verified with the unit cell finite element method. Finally, the effects of structural parameters on the equivalent stiffness of the dimpled sheet were discussed. The analysis results show that with the unit cell finite element method the equivalent stiffness of dimpled sheet can be obtained. The dimpled sheet has higher bending stiffness but lower tension and shear stiffness compared with the base flat sheet. When base sheet's thickness is fixed, the bending stiffness increases as the thickness of dimpled sheet increases, while the tension stiffness and the shear stiffness decrease. As the periodic distance of dimpled sheet increases, the tension stiffness and the shear stiffness increase, while the bending stiffness decreases.
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表 1 单胞结构6种单位应变载荷的周期性边界条件
Table 1. Periodic boundary condition for six unit strain loads of unit cell
应变 u(p, y, z)-u(0, y, z) v(p, y, z)-v(0, y, z) w(p, y, z)-w(0, y, z) u(x, p, z)-u(x, 0, z) v(x, p, z)-v(x, 0, z) w(x, p, z)-w(x, 0, z) =1 p 0 0 0 0 0 =1 0 0 0 0 p 0 =1 0 p/2 0 p/2 0 0 =1 pz 0 -p2/2 0 0 0 =1 0 0 0 0 pz -p2/2 =1 0 pz/2 -py/2 pz/2 0 -px/2 表 2 波纹板与基础薄板的刚度特性
Table 2. Stiffness properties of dimpled sheet and base flat sheet
刚度 波纹板 基础薄板 波纹板与基础薄板刚度比值 A11/(N·mm-1) 24 069 38 716 0.622 A12/(N·mm-1) -162 12 776 -0.013 A22/(N·mm-1) 24 069 38 716 0.622 A66/(N·mm-1) 6 558 12 970 0.506 D11/(N·mm) 1 015 806 1.26 D12/(N·mm) 517 266 1.944 D22/(N·mm) 1 015 806 1.26 D66/(N·mm) 1 165 270 4.315 -
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