Designing with Composites
Advanced composites are seen as a relatively new material in the civil and architectural markets. Although they are becoming more widely used there are some aspects of the materials which can discourage consideration of the materials. These are often misconceptions, and these concerns can frequently be addressed through intelligent design of the structure.
COSTS
Advanced composites can appear to be uncompetitive on price with traditional materials. Manufacturing cost of advanced composite facade panels is maybe two, three or more times the cost of a glass reinforced concrete (GRC) or aluminium skinned foam sandwich standard cladding panel. This initial cost comparison can prevent any further investigation of the material. However the knock on effect of using composites in reduced substructure requirements, installation costs and time on site can result in the overall cost of the composite option being competitive with traditional materials.
DESIGN
Structural design in the civil and architectural markets is based on limit state design codes. Codes for traditional materials are well established, and in many projects design budgets are limited, restricting scope for first principles engineering and leading designers to use familiar solutions
Design codes for FRP are available for specific structures, such as UK Highways Agency BD37 code, and limit state design can be carried out using load cases defined for the structure with partial factors from a recognised guide. However the design of FRP structures for standard structures may take longer than traditional materials as there are fewer standard solutions or past history available for use in the design. However time spent in design will generally allow the development of a structural concept which is appropriate for the materials which will generally give a more effecient structure with reduced material and build costs. Gurit have experience of structural engineering large composite structures over a wide range of industries, and can advise on suitable structural concepts early in the design phase.
FIRE PERFOMANCE
Fire performance can be a critical consideration in design of architectural structures. Materials such as GRC and aluminium count as non combustible, and as the advanced composites used in structures for these projects is unlikely to meet the standards to count as non combustible, additional fire testing will be required depending on purpose the material is being used for. Previous projects in the architectural market have specified BS (British) or NFPA (American) standards. Gurit have experience of developing solutions to meet a range of fire requirements, including requirements for blast protection walls in the oil and gas industry and also for train and aircraft interiors.