School of Civil Engineering

Mentor: Kim Baber, Joe Gattas

Top image from: http://www.extechinc.com/about-us/news/181-cellular-polycarbonate-modern-material-in-aircraft-hangar-design-and-construction.html 

Project TeamJordan Hunter, Anna Vallero, Jack Buckhorn, Kevin Plasencia, Frazer McCloy, Sophie Wier


Project Brief

Materials can ‘behave’ in different ways, dependent upon their internal composition and the scale in which they are deployed in buildings. Material science has invented many new materials, many of which behave structurally at a micro or molecular scale. At the other end of the material scale, advances in fabrication technology have allowed a new range of ‘composite’ materials to be invented that combine the beneficial properties of two (or more) materials to behave in a specific and often unique way.

Students in this Icarus project are invited to work with students in the UQ School of Architecture to will be investigate novel developments of composite materials/structures that combine transparent and translucent sheet materials such as polycarbonate, fibreglass, and acrylic, with CNC machined timber. The intent is to investigate composite materials/structures in which the combination of 2 materials could be stronger than the sum of its parts, but also yield unique architectural qualities in the way that they transmit light into space, and also potentially, ‘dematerialise’ the presence of the structure.

Image: Plasencia Auditorium and Congress, Architects: Selgas Cano


Project Report

Introduction

Current fabrication technology allows a range of composite materials to be invented which combine the beneficial properties of two (or more) materials where the sum of the materials can be stronger than the sum of its parts. Coupled with particular architectural interest  into materials with light transmitting qualities,  the challenge was created to create a composite transparent/translucent structure with a high strength capacity. Developments in technology have allowed these composite structures to be constructed which offer unique strength and aesthetic properties.

Background

The aim of the project was to investigate novel developments of composite materials/structures that combine transparent and translucent sheet materials such as polycarbonate, fibreglass, and acrylic, with CNC machined timber. The intent is to investigate composite materials/structures in which the combination of two materials could be stronger than the sum of its parts, but also yield unique architectural qualities in the way that they transmit light into space, and also potentially, ‘dematerialise’ the presence of the structure. Aided by computer software, the team was able to develop an accurate model which could be constructed using appropriate equipment.

Results

Timber base core sections were arranged into a sandwich panel grid to add a strength component to an outer layer of transparent corrugated polycarbonate. The timber base core sections where created using parametric computation with Rhino plug-in Grasshopper to describe the geometry of the pieces to adapt to the ondular corrugation of the polycarbonate sheets. The purpose of this was so that contractions in the corrugations caused by bending were accurate given the altering radius of curvature of the bend for the inner and outer sections. Prototype testing under 3-point bending and axial compression tests helped determine load capacities for different grid spacing within the timber core. 

Conclusions

With modern architecture exploring of unique transparent/translucent structures, a problem has been created with regards to the structural properties of such assemblies. The developed composite sandwich panel demonstrated the benefit of the polycarbonate as it was able to keep the structure upright and strong despite large deformations and buckling to the timber component. The combination of timber and translucent polycarbonate was considered to be an effective composite structure which provides desirable aesthetic and structural properties, however further research should be done to increase the structural capacity for optimal commercial use.

Figure: Early prototypes

Figure: Rhino/Grasshopper component development

Figure: Final structure