Numerical analysis of perforated bending-active plates integrated in unitized curtain wall

Abstract

Unitized curtain walls with integrated sun-shading systems have become a prevalent choice for high-rise building façades. The present paper presents a novel sun-shading façade system comprising bending-active plates made of glass fiber-reinforced polymer (GFRP) arranged in three series vertically. Each elastic plate is supported at the corners by diagonal steel members, which are paired and equipped with rotating actuators to modify the opening angles. This modification induces elastic deformations on the bending-active plates, altering their shapes to provide varying levels of sun protection. The steel members act as scissor-like elements, supported on the curtain wall mullion using extruded aluminum pressure plates and U-channel rails. The bending-active plates serve as external horizontal louvres, offering adaptive sun-protection. A numerical investigation of a bending-active plate’s structural behavior is conducted through Finite-Element Analysis (FEA). Various symmetric curvatures of the plate are achieved through actuation of the scissor-like elements at specific opening angle values. The analysis considers the self-weight of the plate and a uniform distributed wind load of 1 kN/m². The study explores three different plate thicknesses (4, 5 and 6 mm) in selecting the most favorable thickness. The plate with a selected thickness is then perforated by 15, 21, 28 and 36% of the total area. Two alternative perforation patterns are examined for each perforation percentage. The analysis delves into the form-finding and load-deformation behavior of the bending-active plate, shedding light on the structural integrity and functionality of the sun-shading system.