Laboratory tests and numerical analysis of aluminum helping hand brackets with polyamide thermal break

Abstract

The developments in materials science and engineering, especially in the field of composites and polymers, have extended the scope of application of such materials in modern industrial construction. This article presents polyamide/ aluminium helping hand brackets, designed for use in rainscreens (a.k.a. ventilated façades) and metal and glass systems. The main purpose of this study was to assess the loadbearing capacity, safety and durability of these elements through laboratory tests and numerical analyses. The laboratory tests were carried out on a three-dimensional test stand. Boundary conditions and the applied loading represented real conditions on the façade (e.g. a typical wind pressure load acting on the façade was used). Next, the experimental results were used to build a representative numerical model. Finite Element analysis was utilised to obtain a true representation of the actual behaviour of the analysed brackets subjected to various loads, taking into account the aluminium/ polyamide interaction. Constitutive behaviour of both materials, polyamide and aluminium alloy, was represented by a linear elastic model. The proposed modelling methodology was validated through full-scale load tests up to failure. The numerical model can be further used to predict the stress and strain fields in newly designed brackets subjected to any type of loading.