http://www.thestressmanagementguide.com/blog/stress/does-tensile-stress-and-breaking-stress-depend-on-the-cross-sectional-area-of-the-wire Less Stress = More Fun! Thu, 09 Sep 2010 21:14:37 +0000 http://wordpress.org/?v=2.7 hourly 1 http://www.thestressmanagementguide.com/blog/stress/does-tensile-stress-and-breaking-stress-depend-on-the-cross-sectional-area-of-the-wire/comment-page-1#comment-7049 Ameer Tue, 19 Jan 2010 14:17:59 +0000 http://www.thestressmanagementguide.com/blog/stress/does-tensile-stress-and-breaking-stress-depend-on-the-cross-sectional-area-of-the-wire#comment-7049 Stress in a component is the applied force divided by its cross sectional area, so it doesn't depend on the cross sectional area. However, the area will determine the force required to achieve that stress. A large cross section would require larger force than a small cross section for example, but the ratio would be the same, i.e we will end up with the same value for stress. Tensile stress, or more correctly called the ultimate tensile strength, UTS, is the maximum stress a material can withstand before it starts to break. After this a tensile specimen would exhibit necking, a reduction in cross sectional area, that if it is a ductile material, then it would snap, or breaks when the remaining cross sectional area is not sufficient to withstand the applied force and this stress is called the breaking stress. A brittle material would not experience necking, or reduction in cross sectonal area it would snap, and usually the UTS equals the breaking stress in these materials. Unlike UTS, the breaking stress has no meaning from mechanical design point view. UTS can be used to compare between different materials. However, in design the yield stress is used, which is the maximum stress the material can take before deformation becomes permanent, or plastic. Below the yeild stress, the material is siad to be in the elastic region, i.e any deformation is reversible, when force is lifted the compnent's dimensions return back to original values. Furthermore when you design a component you take a safety factor, to make sure that it doesn't fail, for example 75% of the yield stress. In conclusion, the yield stress, UTS and breaking stress are material properties. Steel for example has higher UTS than Aluminium. Heat treatments and addition of alloying elements can increase these stresses.<br><b>References : </b><br> Stress in a component is the applied force divided by its cross sectional area, so it doesn’t depend on the cross sectional area. However, the area will determine the force required to achieve that stress. A large cross section would require larger force than a small cross section for example, but the ratio would be the same, i.e we will end up with the same value for stress.
Tensile stress, or more correctly called the ultimate tensile strength, UTS, is the maximum stress a material can withstand before it starts to break. After this a tensile specimen would exhibit necking, a reduction in cross sectional area, that if it is a ductile material, then it would snap, or breaks when the remaining cross sectional area is not sufficient to withstand the applied force and this stress is called the breaking stress. A brittle material would not experience necking, or reduction in cross sectonal area it would snap, and usually the UTS equals the breaking stress in these materials.
Unlike UTS, the breaking stress has no meaning from mechanical design point view. UTS can be used to compare between different materials. However, in design the yield stress is used, which is the maximum stress the material can take before deformation becomes permanent, or plastic. Below the yeild stress, the material is siad to be in the elastic region, i.e any deformation is reversible, when force is lifted the compnent’s dimensions return back to original values. Furthermore when you design a component you take a safety factor, to make sure that it doesn’t fail, for example 75% of the yield stress.
In conclusion, the yield stress, UTS and breaking stress are material properties. Steel for example has higher UTS than Aluminium. Heat treatments and addition of alloying elements can increase these stresses.
References :

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