Generalized parameters of composite membrane structures

Abstract

Introduction. Knowledge of the key parameters that determine the operation of load-bearing systems makes it possible to ensure safe, rational and economical operation of buildings and structures. The paper defines the relative generalized parameters that determine the operation of composite membrane structures for membrane systems with a concrete layer placed on the membrane.

Materials and methods. Membrane systems with a rectilinear support contour rigidly fixed on supports and a flat steel membrane attached to it are considered. The calculations were performed for the construction of two dimensions in the plan. The first one is: a = b = 6 m with a membrane thickness of 1 and 2 mm. The second one is: a = b = 12 m with a membrane thickness of 2 and 3 mm. A layer of concrete B30 is laid on the membrane, equal to 50 and 40 mm for the first model, and 100 and 60 mm for the second. The structure along the free edge of the membrane is loaded with a load q acting in the plane of the membrane.

Results. Numerical calculations performed using the finite element method have shown that an increase in the relative longitudinal stiffness of the concrete layer leads to a decrease in bending moment, longitudinal forces in the contour and stresses in the membrane. This increases the rigidity and load-bearing capacity of the structure. It was found that by changing the stiffness parameters of the concrete layer, the efficiency of the structure can be significantly improved.

Conclusions. The placement of a concrete layer on the membrane significantly increases the operational reliability of the structure, reduces forces in the support circuit, and reduces deflections and stresses in the membrane. The relative generalized parameters of membrane systems with a concrete layer can be used to assess the stress-strain state of sagging membrane coatings on a rectangular plan with a flat support contour.