Burst strength analysis of composite overwrapped pressure vessel using finite element method

The purpose of this numerical study was to investigate the burst performance of a type III composite overwrapped pressure vessel (COPV) using finite element methods. An Aluminum overwrapped composites pressure vessel was modeled from four layers of carbon fiber/epoxy ply with 0.762 mm and arranged in two different sequences and orientations. The overwrap composite pressure vessel burst performance was examined by applying an internal pressure of 55 MPa on a ply arrangement of [-15°/0°/+15°/90°] and other research findings on [+55°/-55°] as an optimum filament winding angle were used for comparison purpose. Moreover a ply level orientation effect analysis, which is a superior feature of ABAQUS, was used for the composite modelling. The designed ply sequence and orientation exhibit a higher burst pressure at [0°] ply and minimum at [90°] ply orientation. The vertical COPV design displays a maximum stress along the axial direction that leads to the consideration of maximum vessel thickness to be along axial direction for burst resistant design of COPV.

Toroidal uniformly stressed pressure vessel shell formed by the meridian and ring filament winding

The paper outlines the prospects for the use of composite toroidal high-pressure cylinders for the breathing apparatus of the Ministry of Emergency Situations, fire brigades, industrial workers, which are more ergonomic in comparison with their cylindrical counterparts. Relying on the analytical solution of the equilibrium equations, we determined the shape of the cross-section of toroidal shells reinforced along the meridians and representing intersecting loop-like curves that form an infinitely long corrugated pipe. The study introduces a solution for a toroidal composite pressure vessel formed by the intersection of the upper and lower branches of the shell, reinforced along the meridians, and a profiled ring layer of filaments installed at the point of their intersection. The parameters of the toroidal uniformly stressed pressure vessel shell made by ring and meridian filament winding are calculated.

Fracture analysis of composite pressure vessel using FEM

A finite element-based numerical method is applied to predict the possibility of propagation of existing delamination/patch in a filament wound composite pressure vessel in this work. Strain energy release rates (SERRs’) in the three principal modes are predicted along the circumference of delamination for two different load cases, i.e., internal pressure load when two diametrically opposite patches are existing in the nozzle end side dome portion, and combined load due to thrust and bending when a patch is located in the nozzle end side skirt region of the composite pressure vessel (CPV). The problem is modeled in ANSYS software and a three-dimensional finite element approach in association with virtual crack closure technique (VCCT) is used to analyze the fracture behavior of the CPV under two load cases as stated. In both the load cases, SERR is found to be maximum at the bottom side of the patch, Mode-I being dominant under pressure load, and Mode-II in axial load. Delamination growth is observed at 26.5% of applied pressure in Case-1 and 57.5% of axial load in Case-2. This fracture analysis approach can be extended to composite structural components in defense and aerospace applications.

Numerical Analysis of Filament Wound Cylindrical Composite Pressure Vessels Accounting for Variable Dome Contour

In this work, the stress distribution along cylindrical composite pressure vessels with different dome geometries is investigated. The dome contours are generated through an integral method based on shell stresses. Here, the influence of each dome contour on the stress distribution at the interface of the dome-cylinder is evaluated. At first, the integral formulation for dome curve generation is presented and solved for the different dome contours. An analytical approach for the calculation of the secondary stresses in a cylindrical pressure vessel is introduced. For the analysis, three different cases were investigated: (i) a polymer liner; (ii) a single layer of carbon-epoxy composite wrapped on a polymer liner; and (iii) multilayer carbon-epoxy pressure vessel. Accounting for nonlinear geometry is seen to have an effect on the stress distribution on the pressure vessel, also on the isotropic liner. Significant secondary stresses were observed at the dome-cylinder interface and they reach a maximum at a specific distance from the interface. A discussion on the trend in these stresses is presented. The numerical results are compared with the experimental results of the multilayer pressure vessel. It is observed that the secondary stresses present in the vicinity of the dome-cylinder interface has a significant effect on the failure mechanism, especially for thick walled cylindrical composite pressure vessel. It is critical that these secondary stresses are directly accounted for in the initial design phase.

Investigation of hybridized composite pressure vessel

Burst pressure is the vital parameter to be strong-minded for their design. Burst pressure is the pressure at which vessel crack and core fluid seep outs. A design shelterbound that ought to not be surpassed. Further than this pressure possibly willescort to mechanical fall foul of and enduring loss of pressure restraint. The present work is aimed in studying the pressure vessel (PV) made with composite material. During the study the PV is fabricated by glass fiber with 90O fiber angle and performed hydrostatic test. Later the same PV is modeled in Ansys and analyzed with various fiber angles to determine the failure by considering their deformation, stress and strain of the PV using GFRP, CFRP and hybrid composites. At last the results obtained are validated.