Introduction and Literature Review Context Freeform surfaces prevail in contemporary architecture. Over the past two decades there has been a surge in the use of smooth, curved surfaces, which can be attributed to improvements in 3D modelling techniques and advances in finite element analysis. The complex geometries, examples of which can be seen in the Figure ? below, pose challenges in developing a feasible building envelope using conventional building materials such as steel and concrete. This has therefore created a need to investigate the suitability of alternative building materials such as glass fibre reinforced polymers (GFRP) to structural design. In construction, geometrically complex free form shapes are realised by simpler, individual panels, which must be manufactured to high tolerances in order to fit together and satisfy their purpose. A material which lends itself to prefabrication and lightweight construction, is therefore desired. It is worth mentioning here that the issue of efficient panelling or rationalisation is a broad research interest separate from that of material selection [1], and will not be addressed in this report, the focus here being on structural suitability and modelling. Glass Fibre Reinforced Polymers (GFRP) Glass fibre reinforced polymers are composed of glass fibres nested in a polymer resin matrix. The glass fibres provide stiffness and tensile strength, whilst the resin matrix binds the material together, provides compressive strength and transfers the loads to the fibres. The final product is impermeable, corrosion resistant and weather resistant which makes it suitable for long-term use in external conditions. Its specific strength is high, typically exceeding that of both ... ... middle of paper ... ...acture, and Damage Theories. Courier Dover Publications, 1991. [21] Bryan, G.H., “Proc. London Math. Soc.,” vol. 22, p. 54, 1891. [22] S. P. Timoshenko, “Bull. Polytech. Inst.” 1907. [23] S. P. Timoshenko and J. M. Gere, Theory of Elastic Stability, 2nd edition. Mineola, N.Y: Dover Publications Inc., 2009. [24] M. W. Darlington and P. H. Upperton, “Procedures for Engineering Design with Short Fibre Reinforced Thermoplastics,” in Mechanical Properties of Reinforced Thermoplastics, D. W. Clegg and A. A. Collyer, Eds. Springer Netherlands, 1986, pp. 205–248. [25] B. Committee, “BS EN 1991-1-1:2002 - Eurocode 1. Actions on structures. General actions. Densities, self-weight, imposed loads for buildings,” BSI, 2002. [26] F. L. Matthews and R. D. Rawlings, Composite Materials: Engineering and Science, 1 edition. Woodhead Publishing, 1999.
Laws such as the lever law and Euler’s Buckling Theorem come into play when testing and competition begins. A structure of wood and glue surely has much more to offer than meets the eye.
These structural differences direct the use of these materials in WPC. For instance, fiber dimensions, strength, unpredictability, and structure are important consideration. Maldas et al. have investigated the result of wood species on the mechanical properties of wood/thermoplastic composites [7]. They reported that differences in morphology, density, and aspect ratios across wood species account for varying strengthening properties in thermoplastic composites.
Packable composites have a higher filler load and elastic modulus than flowable composites. Packing might also reduce shrinkage. Flowables have less filler and are used as liners and sealants. They cannot withstand much force, but this helps relieve stress due to shrinkage. However, this may be counteracted because they shrink upon curing. Flowable and packable composite resins were tested for shear strength 30 minutes, 1 day, and 1 week, after curing under constant pressure. The dimethacrylate resins tested were: Alert/- Flow It, Filtek P 60/Filtek Flow, Admira/Admira Flow—an ormocer resin—and a microfill composite resin. The resins increased in strength over one week. The packable composites were stronger than the flowables, but variable between manufacturers. The ormocer resin had a lower elastic modulus than other packable resins. Although the flowables have lower elastic moduli, they shrink more, so shrinkage stress might not be better than packable composites. (Helvatjoglu et al)
Polymeric materials play a functional role in every aspect of daily life, from clothing to infrastructure. Polymers differ greatly from other materials, such as ceramics or metals, based upon the types of bonding. Metals bond metallically, creating a sea of electrons, and ceramics generally bond ionically, strongly tying electrons to lattice points. Polymers bond covalently in carbon chains, which (in general) make their properties more variable due to the possibilities of arrangement in bond length, angle, and molecular configuration. Polymers, on average, tend to be more lightweight, have a greater range of colors, lower thermal and electrical conductivity, less brittleness, more resistance to acids, bases, and moisture, and higher dielectric strength than their ceramic or metallic counterparts, but with great range. This variety of properties leads to a variety of classifications, and therefore differing processing methods based on the classification of polymer.
My structure has to bear a lot of heavy loads which vary seasonally through out the year
Some limitations that occur when producing carbon fiber composites is the price that it takes to make the material, the quality of the fibers, and the quality of the process. As illustrated earlier in this paper, the procedure of making carbon fiber composites has many procedures and with each additional step comes the opportunity to make an error. Wither it is oxidation, carbonizing, or treating of the strands, all have potential of error if not done correctly which would lead to an inferior product. Then manufactures have a choice of epoxy and of desired weave. Both of these allow the final product to have different characteristics depending on the chosen technique. Lastly, a major limitation that occurs with carbon fiber composites is the
Carbon-fiber-reinforced-polymer (CFRP) is a composite polymer made up of carbon fibers and a binding polymer. The binding polymer can be a thermoset resin or thermoplastic polymer(s). Examples of thermoplastic polymers that can bind with carbon fiber to make CFRP are polyester, nylon, or vinyl ester. A thermoset resin that can combine with the carbon fiber to make CFRP is epoxy. The combination of the carbon fibers and a thermoset resin or thermoplastic polymer producing CFRP results in a light weight fiber-reinforced plastic that is tremendously strong. Depending on the binding polymer, CFPRs have a wide range of applications and are used when a light weight material with high rigidity and strength are required.
When building sandwich composite structures, the materials are shapeable in almost any kind of form until the last stage of production in which they get their final shape. This allows for non-linear and smooth designs, which can be done not only for aesthetic reasons but also for aerodynamic reasons. Other advantages of using sandwich composites are that they provide thermal insulation, sound insulation, good corrosion resistance, resistance to moisture, and final structures can be repaired easily.
Buildings consume a variety of materials in their construction. Green design reduces the dependence on resource intensive products and materials. Today, there are an increasing number of products available made from efficient, earth-friendly, or recycled materials. In a green building, consideration is also given to the construction process itself. Materials that minimize waste or can be recycled, help contribute to an efficient and environmentally sensitive construction process.
Concrete has been cast in rigid formwork since it was invented. The traditional rigid formworks are constructed using flat, straight sheets with uniform section built with 90-degree joints [1]. The resulting forms are simple, uniform cross-section shapes. However, uniform section or prismatic shapes are not always the most desirable. Unlike the rigid formwork, fabric formworks
Polymer Matrix Composites are the most common and will the main area of discussion in this guide. Also known as FRP - Fibre Reinforced Polymers (or Plastics) these materials use a polymer-based resin as the matrix, and a variety of fibres such as glass, carbon and aramid as the reinforcement. Metal Matrix Composites are increasingly found in the automotive industry; these materials use a metal such as aluminium as the matrix, and reinforce it with fibres such as silicon carbide.
In the field of civil/structural engineering, many design industries use the optimisation technique to demonstrate the conceptual design; mostly applying to the entire structure that provides novel layout of the framing system. However, not much has been accomplished on the component level. Even though application of topology optimisation concepts on structural components are presented as illustrative examples in research papers, they are mainly restricted to show various methods of optimisation. Hence, practicality of the result is not
Given such advantages as low weight compared to strength and toughness, laminated composites are now used in wide range of applications. Their increasing use has underlined the need to understand their principle mode of failure
This is the textbook for my materials science and engineering class. It contains information about the behaviors and properties of materials such as metals and polymers. This source will prove useful because in the field of tensegrity, the type of material used to make a structure is very important. In the field of engineering/tensegrity, this source is considered as a reference
The concerns with inferior fracture toughness of concrete are alleviated to large extent by reinforcing it with fibers of various materials. The resulting material with a random distribution of short, discontinuous fibers is termed as fiber reinforced concrete (FRC) and slowly becoming a well-accepted mainstream construction