Study On The Fatigue Property Of The PVC Calendered Flexible Composites

In the recent years, PVC calendared composites have been widely used in tenting, advertising banner, geo-textile field, lightweight structures and so on. As newly arising materials, it has great potential in the future markets. When flexible composites are used in available circumstances, it will inevitably suffer various out forces time after time. This will bring fatigue effect, which will do harm to the mechanical properties and its service life. So the study on its properties is more and more important. In the present markets, the reinforced parts of flexible composites are mainly woven fabric and warp-knitting bi-axial fabric.In this thesis, we mainly study on the fatigue performances of the calendared flexible composites reinforced with weaving fabrics. Five samples were selected which were of different structures and different yarn count while using the same PET filament yarn and the same PVC as the raw material. Besides the tests of the weight per square meter, the yarn count and the thickness of the samples, the tests for the tensile break property and the fatigue property were as the main work. Based on the datum, comparison and analysis are necessary to come out with the conclusions.Referring to Standard Test Methods for other composites materials and the datum of the above tensile break tests, Tension-tension fatigue test plans are lay out and observed.After the testing, the drawing of the corresponding curves helped to build the mechanics models for simulation. According to the simulation results, the service life of the materials can be forecast. The testing results of the mechanical performances after the fatigue experiments were used to evaluate the performance decline. Based on these fatigue tests, Peeling tests are carried out. Correlative factors of fatigue performances, such as tensile times, elongation ratios, structure and yarn count, re analyzed and evaluate the peeling performances decline.Through the tensile and fatigue research, tensile break mechanism and its factors of these materials are obtained which help to lay out reasonable experimental plans. Fatigue experiments validated that the fatigue curve of flexible composites follows the S-N theory and thus therepetition times of fatigue load before the material was tore can be forecasted. Also through the fatigue tests, the conclusion would come out that the mechanical performances of flexible composites would decline if repeated outside forces are acted on it.The conclusions have been got and the work has been done in the thesis will do a great help to understand the properties of the woven flexible composites. For the practical production, they also contribute a certain reference value.In this thesis, however there are still some shortages to be improved in the future. At the end of the paper, a sum-up was made and future development for the flexible composites was forecasted.