Finite element analysis and optimization of multi-layer combined ultrahigh pressure cylinder
The finite element model was established by the finite element method of Workbench. The prestressed state and the working state of the multi-layer composite cylinder was used to calculate by the finite element method. The general distribution law of the stress of the multi-layer cylinder is obtained, and the equivalent stress distribution is not uniform. At the same time theoretically based on the elastic limit of multilayer composite cylinder unified solution, and the optimization condition is determined. The design of multi-layer ultrahigh pressure cylinder is optimized. The results show that the nonuniformity of the stress distribution of the cylinder can be improved greatly. The study can provide technical support for the structural design and optimization of the multi-layer ultrahigh pressure cylinder.
Numerical Analysis on Delta-Ring Seal Structure of Ultra High Pressure Vessel Employed in Food Processing
Due to the characters of the ultra high pressure vessel employed in food processing, a seal structure was introduced in this study. Then numerical analysis was performed using the larger finite element stress analysis software ansys12.0 for the stresses of the seal structure under internal pressure. In order to solve the contact question of delta-ring seal structure by using face-face contact model, a 3-D axisymmetric solid element was employed to calculate the stresses of the connected location among delta-ring, blind cover and end cylinder, the mises stresses in this structure were analyzed. Thus, the distribution nephograms of the stress on the contact surface were obtained in different conditions. Full-field plastic deformation of seal structure was generated when the inner pressure was larger than 300Mpa. At last, the reason for residual deformation was analyzed.
Ductile failure of X100 pipeline steel – Experiments and fractography
Abstract Ductile failure of X100 pipeline steel is studied. In order to study the effect of anisotropy, triaxiality factor and Lode angle on the failure, a series of specimens with different geometries are tested. Measurements of deformation in three dimensions are done to check the variation of elongation and lateral deformations during loading. Extensive fractography is done using pictures taken by SEM to study the fracture surfaces completely. The results show that triaxiality causes the failure to occur sooner and Lode angle has no effect on the failure in triaxialities higher than that of simple tension. Moreover, delamination has occurred in some of the specimens. This phenomenon is studied and the causes of delamination are explained in macro scale.