Finite Element Dynamic Simulation Of The Tensioning Process Of The Core Soft - Bag

The varus process of coring soft bag is a influence factors very complex nonlinear deformation process, just relying on the experimental experience of people or simplified analytical studies, it is difficult to meet the needs of process design. At the same time, it is difficult to understand the specific forces situation of coring soft bag, and the use of experimental research methods are difficult to reproduce repeatedly the influence regular of various factors of coring soft bag trunover lining process, the experimental results only limit one of the species or one of the conditions, and therefore does not have universality. In the trunover lining and pulling process, the deformation behavior of coring soft bag in the ends of the holding core tube is affected by many factors, such as coring soft bag fabric material parameters, thickness, soft bag wrap length, holding the core tube radius and the inner diameter etc, the deformation behavior is very complicated. In order to achieve safe lifting core, the coring soft bag need to ensure that does not happen from locking and destruction.In this paper, coring soft bag for the study, apply of macro-homogeneous and anisotropic equivalence principle to establish coring soft bag model, analytical analysis and dynamic simulate of coring soft bag on the holding the core tube trunover lining and pulling process. At the same time also dynamic simulate the pulling process of coring soft bag on the holding core tube outer wall by the finite element method, as follows:1.Using the similar euler principle to analyze the force situation of the coring soft bag and the outer wall of the holding the core tube, as well as coring soft bag turned inside the outer wall of the holding the core tube according coring soft bag trunover lining and pulling motion, establish mechanical model that reflects coring soft bag trunover lining and pulling process, and study the relationship between the force situation of coring soft bag and the wrap length. The results showed that the stress of coring soft bag is decreases by the wrap length decreases.2.According coring principle to appropriately simplify the coring soft bag on the holding core tube trunover lining and pulling process, and rationalize establish the finite element model of the trunover lining and pulling process of coring soft bag, measured the corresponding material parameters, using anisotropic constitutive models and large deformation shell elements, and dynamic simulate the trunover lining and pulling process of the coring soft bag, and experimental verification. The results showed that the maximum stress of the coring soft bag appears to the holding core tube end, and decreases by the wrap length decreases, and the finite element simulation results and experimental results agree well.3.Based on the coring soft bag material constitutive model, using the finite element method to dynamic simulate the coring soft bag pulling process, and experimental verification. The results showed that the maximum stress of the coring soft bag appears to the pulling head end, and the finite element simulation and experimental results are consistent.4.Respectively studied and analyzed coring soft bag main poisson ratio, thickness, the holding the core tube wall thickness and inner diameter to influences the coring soft bag trunover lining and pulling process. The results showed little effect of different main poisson ratio for the coring soft bag deformation and stress distribution regular; the thickness of the coring soft bag have a greater influence on the forces. when the holding core tube thickness is 1 mm, the coring soft bag suffered the minimal stress; while the inner diameter of the holding core tube is 15mm, the coring soft bag suffered smaller stress compared to other inner diameter.