Research On Tearing Of Thin-Wall Polymer Of End-of-Life Vehicles

With the rapid development of our economy, a large number of vehicles have rushed into home. These vehicles will be scrapped gradually in10-15years. There are a great many of polymer materials on the End-of-Life vehicles (ELV), if these mate-rials were not recycled properly, hundred million tons of polymer wasters will be in-curred. And these wastes will take up much of our land, and pollute ecological envi-ronment heavily, and affect people’s daily life and physical health, and have bad effect on the sustainable economic development of our country. In fact, these wastes could be retrieved by the mode of dismantling, sorting, shredding, and then substitute for pri-mary raw materials. Not only is this mode propitious to make full use of natural re-sources but also benefits ecological environment, what’s more, the new vitality will be injected into the sustainable economic development of our country.At present, the whole machine shredding is main developing trend of recycling ELV. While the tensile and tearing are two main modes of shredding. The purport of research on shredding of thin-wall polymer wastes is to provide a high efficiency and low consumption way for recycling thin-wall polymer wastes of ELV. Thin-wall poly-mer wastes with various uses on different kinds of ELV were randomly chosen as ex-perimental investigation objects, and the tensile and tearing specimens were prepared, then the tensile and tearing test were conducted.Through the tensile tests, the tensile stress-strain curves of the thin-wall polymer wastes on ELV were obtained. And the constitutive relation of typical thin-wall poly-mer wastes was simplified as tri-linear model. The phenomenon that trouser legs of specimens underwent equal and opposite bending deformation twice by analyzing the process of tearing of thin-wall polymer specimens was observed during trousers tearing test. So the total work which the load did was composed of the tearing work of speci-mens and bending work of trouser legs. The bending work was calculated by the tri-linear model in the process of tearing test. The total work took away the bending work left the tearing work, and then the specific tearing work per unit area of new crack surface that was mechanical parameters of thin-wall polymer on resisting tearing was obtained.Through the finite element software, the simulation research on tensile and tearing test of thin-wall polymer wastes of ELV was conducted. And the simulation was com-pared with the test. Then, the correctness and reasonableness of the test were verified. In addition to, six nodes on neutral layer in the tear specimens were tracked. These six nodes initially arranged in straight line, and then gradually bent into circular arc shape, finally returned into straight line. This process confirmed adequately the phenomenon that the tearing specimens underwent equal and opposite bending deformation twice.According to research results, the loading rate affected the specific tearing work within a certain range; the specific tearing work of thin-wall polymer is less than the specific tensile fracture work of the same material, which indicated that thin-wall po-lymers were torn more easily than tensile. Therefore, problems of shredding, selecting and recycling thin-wall polymer wastes on ELV could be solved more efficiently by tearing.