The Cohesive Zone Model Ramie Stalks Interface Based Numerical Analysis

Ramie is unique to China with the ecological functions of natural fiber resources, theramie industry development is an important measure of the large-scale supply of textile rawmaterials and promote the "three rural" issue is resolved. Squeeze due to the three-tierstructure of ramie stem separation and stripping the plastic technical problems, ramiestripping system to become the bottleneck in the development of ramie industry. Research andanalysis ramie stalk mechanical behavior and separation mechanism is the solution to thehemp crop the "stripping difficult to close and design efficient separation of plastic extrusionequipment theoretical basis.Ramie stem from the biological structures with composite structure comparison, ramiestem and composite materials at the macro level similarity: ramie stem the outer layer ofhemp fiber and unidirectional composite material similar to the longitudinal fibers, andsimilarxylem tissue and the matrix of the composite material. Can be unidirectional compositematerial model as ramie stalk, bast fibers and xylem can be regarded as not the same as thedistribution of fibers and matrix composites, bast fiber layer between the xylem and a thinbiological glue. quality, simplified interface, which can be bast fiber layer and xylem simplifyheterogeneous mechanical model of bi-material interface. Research ramie stalk interfaceseparation mechanism, the use of experimental tests the Interface theoretical modeling andfinite element numerical simulation, the establishment of the ramie stem interface mechanicalmodel. Clarify ramie stem mechanical phenomenon and interfacial fracture stress anddisplacement field distribution pattern reveals bast fiber layer, and xylem separationmechanism; critical condition with the criterion to determine the interface crack key factors.The main research content and conclusions are as follows：(1) by cracking damage on the the cohesion models in engineering materials andstructures, especially delamination crack of research and analysis, ideas CZM separation andanalysis of biological materials, and finally experimental test and numerical simulationanalysis method ramie stalkinterfacial separation.(2) describes the the cohesion model theory and cracking damage in engineeringmaterials and structures, especially the delamination crack the application, and ramie stalkbiological structure were analyzed, select the bilinear CZM as ramie stem interface separationmechanical model; (3) Ramie stalk bast fibers and xylem separation in the universal testing machine testtest, tension and displacement curve obtained ramie stalk bast fibers and xylem separation,and in accordance with the construction materials testing standards and requirements ofcohesion model theorycurve fitting analysis.(4) The application of ABAQUS finite element bilinear CZM the stem interfaceseparating analog bast fibers and xylem separation process and the distribution of stress at theinterface.(5) by numerical simulation with the experimental values were compared, according tothe test parameters to adjust the parameters of the bilinear CZM to better simulation ramiestem interface micromechanics, reflecting ramie stem interfacial tension displacementrelationship in the process of crackingand fracture energy.