Abstract: The determination of stress distribution is important for the safe use of membrane structures in practical engineering, which is difficult to be obtained by existing measurement methods and analysis methods. This paper proposes a rigid-membrane method to determine the stress distribution of the membrane, which expands the stiffness of the membrane, applies the load of the membrane in equilibrium to the membrane shape of the equilibrium state, and performs nonlinear finite element analysis. The rigid-membrane method inversely acquires the stress distribution of the membrane based only on the shape and load distribution in equilibrium obtained from the numerical simulation of a membrane structure under water loads, and determines the modulus magnitude and mesh size required to rigidize the membrane. The accuracy of the rigid-membrane method is verified by the small differences between the stress distributions obtained from the proposed method and numerical simulations. The equilibrium membrane shape in the actual project can be scanned and reconstructed by the laser scanner system without any pre-processing, and the load is determined by the water level, internal pressure, etc. Based on the actual membrane shape and water load distribution, the rigid-membrane method determines the real stress distribution of the membrane in the test of flat membrane subjected to ponding water, which verifies that the rigid-membrane method is a practical method to determine the stress distribution only by the membrane shape and external load distribution.

Key words: membrane structures, rigid-membrane method, laser scanner, stress distribution

摘要： 应力分布确定对于膜结构在工程实践中的安全使用至关重要，然而现有的测量方法和分析方法难以获得准确的应力分布。提出了一种刚性膜法来确定膜应力分布，该方法通过扩大膜刚度，将平衡状态下的膜荷载施加到平衡状态的膜形状上，并进行非线性有限元分析。刚性膜法仅基于水荷载作用下膜结构的平衡形状和荷载分布，通过数值模拟反向获取膜应力分布，并确定了刚化膜面所需的模量大小和网格尺寸。通过比较该方法获得的应力分布与数值模拟结果之间的微小差异，验证了刚性膜法的准确性。实际工程中的平衡膜形状可以通过激光扫描系统进行扫描和重建，无需任何预处理，而荷载则由水位、内压等因素决定。基于实际膜面形状和水荷载分布，刚性膜法确定了平面膜承受积水试验中的实际应力分布，证实了该方法是一种仅通过膜形状和外部荷载分布就能确定应力分布的实用方法。

关键词: 膜结构，刚性膜法，激光扫描仪，应力分布