Study On The Notch Sensitivity Of Polymer Under Different Strain Rates

The polymer is one kind of macromolecular material, it is one kind of new materials at the modern times, it has been applied more and more much to machinery, the building and high and new technology field as material of construction whose Mechanics property is most important in the many physics function . When the component is applied as the project by the force, under the loading effect, especially when strain rate is higher, the stress of the notch is the problem that one is very important but not beat out yet. As far as notch sensitivity and strain rate sensibility be concerned, it focuses on the metal material research mainly, notch sensitivity and strain rate sensitivity study of polymer material is still very rare in report.In this paper, two kinds of polymer material that are polypropylene (PP) and Acrylic nitrile-Butadiene-Styrene (ABS) have been chosen, made so many notch samples that have the different notch bottom arc radius (0. 1～1 mm) and different notch depths (1～3 mm),carried out the research of tensile test under different strain rate , carried out correlative comparing and study on the data gaining on to there being no the notch sample and the notch sample respectively. And the nonlinear finite elemental simulative analysis on notch sample has been carried out with finite elemental method software (ANSYS), finite elemental calculative results have been compared with the experimental result. Finally, according to obvious sticky plasticity characteristic in plasticity deformation, viscoplasticity constitutive relation of two kinds of polymer material has bees analysed.Result of the experiment shows that the general average value of notch sensitivity ratio(NSR) of PP and ABS notch sample all greater than 1 under different strain rate , PP and ABS are no sensitive to notch under different strain rate, and PP and ABS are sensitive to strain rate. The calculative result of Finite element method supports the experiment result. PP and ABS viscoplasticity constitutive relation are expressed being a over stress theory form including corresponding material parametric.