The Research On Long-Term Creep Behavior And Finite Element Analysis Of Geogrids

Geogrid is a new type of geosynthetics, which have strengthening, reinforcing, protecting functions and were widely applied to highway, railway, irrigation works, coal mine etc. Geogrids were subjected to long-term tensile force in the groundworks during its applied process, which is a long-time creep process. So, geogrids' creep property is important guideline to characterise its mechanics performance. The research of Geogrids' creep property was conducted by the thesis. As a part of the project of "Geogrids' moulding technology and equipment", this thesis conducted research thoroughly for the Geogrids' creep test and long-term creep behavior on the basis of the work which have finished.Geogrids were made from the polyolefin sheets which were first punched with a regular pattern of holes, and then heated and drawn uniaxially in the machine direction, so it has different creep mechanisms and model compared with ordinary polyolefin products. It is a chief step to construct creep mathematics model on the basis of testing data of Geogrids' creep behavior.Geogrid specimens were tested under different loads with creep experiment devices equipped meter and air-condition, which is the basis of studying its creep behavior. Then there is a need to deal with the experiment data correctly, which can get valuable conclusions. The one purpose of studying geogeids' creep behavior is to predict its life span. One of predicting methods of is to extrapolate its creep behavior based on the combination of testing data and theory formula. To solve the problems (limit of testing time) which can't be resolved through the creep test practically, simulating creep procedure by applying finite element method (FEM) is another effective method. The stress distribution, strain distribution, and long-term creep results of geogrids' different part can be attained with the FEM to simulate creep behavior of geogrid specimen. Moreover, we can offer useful references for improving production technology and accurate prediction of geogrids' long-term creep behavior.At present, the research on geogrids' creep behavior remains vacancy at home. Also, theinfluence of geogrids' creep property on its applied procedure is large. So the work of the thesis will have significant meanings for the theoretic research and geogrids' production & application.