Effect of Specimen Preparation Methods for Tension Test on Design of Cold-Formed Steel Members

Steel material used in building needs a heavily production process and it has a big cost to be manufactured. So the material amount used in constructions must be reduced in order to achieve a non-polluted environment due to heavy steel production industry. The reduction of steel has to be managed by lowering the weight of the steel that used in construction by a qualified design without lowering the quality of the material. [2]. So, it is needed to understand the behavior of the material or mechanical properties under various tests such as tensile testing, compression or flexural testing. Since, the strength of the material is the main issue in determining the enough plastic deformation that the material can withstand, the behavior of the material is inspected under various tests like tensile testing. Tension tests provide information on the strength and ductility of materials under uniaxial tensile stresses. This information may be useful in comparisons of materials, alloy development, quality control, and design under certain conditions. Tensile properties are often used to examine the behavior of the material under uniaxial loading. It is going to be examining the most useful method to prepare the tension test specimen for design of cold form steel member [3]. Sheet metal forming is the process that materials undergo permanent deformation by cold forming to produce the member. The process is carried out by in the plane of the sheet by tensile forces with high ratio of surface area to thickness. Tension specimen can be prepared by different methods from cold formed sheet metal. Common cutting methods will be examined. Inspected methods are computer numerical control laser cutting with oxygen, laser cutting wire nitrogen and wire electrical discharge machine cutting. All these methods have own advantages, but different effects on specimens. Some measured properties that must be considered when designing a cold formed steel structure include tensile strength, yield strength and modulus of elasticity. The other important property is ductility that is the ability for plastic deformation in tension or shear. Ductility controls the amount a material can be cold formed that is the process used when producing cold formed steel members [5]. Ductility is the measure of how much the material can be deformed before fractures. Ductility is rarely incorporated directly in the design; rather, it is included in material specifications to ensure quality and toughness.