However, the changes seem minor if we look at the results, and the data from the white PA can be used as reference. A tensile strength of 48MPa along the layers and of 35MPa perpendicularly to the layers.Įffects of dyeing Dyeing is a treatment wherein our plastic is dipped in a dyeing bath at an elevated temperature, which may change the properties of the material.A strain at break of 21% along the layers and of only 8% perpendicularly.A Young’s modulus of 1,78GP for horizontal prints and 1,52GPa for vertical prints.When pulled perpendicularly, the material yields more easily than in the direction of the layers. Indeed, cohesion between two layers is weaker than between the grains of powder of a same layer. That is what we call an anisotropic material. Homogeneous materials: White Plastic (PA12) Our white plastic objects are made thanks to Laser Sintering, layer by layer, which means that the properties of our material are not the same in every directions. Tests have been performed on flexible Plastic, Nylon, black Nylon, glass filled Nylon, Carbonmide and Alumide. After this,the This is where it will break, but as it is linked to a lot of variables, such as the geometry of the object, it is difficult to know exactly when it will occur. Finally, if the strength applied is too big, then the material will reach the ultimate strength point rupture point.For example, modeling clay always has a plastic behavior. Beyond the elastic limit, the material will have a plastic behavior, and permanent deformation will occur.Before the first yield point, the material will have an elastic behavior, which means that it will go back to its initial state if we release the applied strength.Each of these behaviors are separated by yield points on the engineering stress-strain curve: There are mainly 3 types of behavior for a material, depending (among other variables) on the strength you use to deform it. It has no unit.Ī rod of 10 cm at rest that is 15 before at break has an elongation at break of 0.5 sometimes written 50%. What is elongation at break ?Įlongation at break is the elongation that a material can withstand before breaking. It’s important to notice the difference between resistance and elasticity.Ī rubber band is easier to deform that a spaghetti but it’s harder to break. This is the limit between plasticity zone and rupture zone. Tensile strength is the value of the maximum stress that a material can handle. – s is the transverse section in m² or in²Īpplying a 400Kilo-force (4000N) to a 2cm radius (0.00126 section) 2 meter long steel rod with a Young’s modulus of 200 GPa, the rod will deform off 4000/(0.00126* 200.000.000)=0.016 and the rod will now measure 2.032m What is tensile strength? Epsilon is the elongation (Length / original Length) no unit
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