The Research On The Relationship Between The Polycarbonate Sheet Specimen Dimension And Plastic Target

Polycarbonate (PC) is a kind of thermoplastic macromolecular material, which has ideal properties of mechanics, optics and thermotics, and got the name"The best of engineering material". So, it's widely used in many fields. As the closing relationship between the mechanical property and the material forming property, the method of tensile test was used in the sheet-forming field for the prediction of sheet property, such as the plastic target—the total elongationδand aera reductionψetc. In the practice, the total elongation was used in the prediction of sheet property because the measurement of the area reduction was difficult. But many countries have themselves standards that different to each other, different specimen dimension brings out different total elongation, so the influences of length, width and thickness of the specimen on forming property were studied in the paper.First, the relationship between the specimen dimension and the total elongation was testified using orthogonal test. The influences of specimen length, width and thickness on the total elongation were studied by the range analysis, and the influences degree of the three factors on the total elongation were compared by the variance analysis, so the factor influence profound were located.Based on the test data, the paper simulated the specimen which have different geometry size by the Finite Element Method. Through the multiple simulation, the effects of the specimen dimension on the total elongation were analysed, and the relationship between them was studied.In the last, through the analysis of the strain-stress curves and the distribution of strain and stress of the specimen, the case that different specimen dimension brings out different plastic were interpreted.