有限元模拟膜张力计的平面内张力-平面外位移关系

Finite Element Simulation of Membrane Tensiometer's Relationship between the Inplane Tension and the Transverse Deflection

膜结构施工中膜张力的测量与控制以及使用中膜材张力的检测,是确保膜结构稳定与安全的重要因素。膜张力计是一种简便实用的装置,可以在不破坏膜材且不影响膜内力分布的条件下分别测定纬向和经向的张力。本文用有限元软件ANSYS模拟膜张力计测量FGT-800膜材的初始张力,分别沿着纬向和经向在压力容器范围内施加平面外均布荷载后,通过计算膜平面外最大位移来推算膜平面内纬向和经向的初始张力。用最小二乘法拟合有限元分析结果,得出了更合适的膜张力拟合公式,其中膜张力简化拟合公式相对误差在±4%之内,膜张力联立拟合公式相对误差在±2%之内。

The measurement,monitoring and control of membrane tensions in membrane structures are important for the stability and safety of membrane structures.The membrane tensiometer can be used to measure woof and warp tensions of the membrane without breaking membrane or influencing the internal stress distribution.The finite element software ANSYS is used to simulate the membrane tensiometer measuring of the initial tensions for FGT-800 membrane.After exerting uniform pressure load onto the membrane within the pressure vessel along the woof direction and warp direction,respectively,the transverse maximum deflections are calculated and the inplane initial woof and warp tensions of the membrane are projected.The finite element analysis results are well fitted by least squares method,and more appropriate membrane tension fitting formulas are obtained.The relative errors of the simplified membrane tension fitting formulas are within ±4%,and the relative errors of the coupled membrane tension fitting formulas are within ±2%.