Computation of Deformation and Burst Pressure of Cylindrical Composite Pressure Vessels under Low Impact Velocity

ENGINEERING COMPUTATIONS AND SIMULATIONS
Name
Institution

Computation of Deformation and Burst Pressure of Cylindrical Composite Pressure Vessels
under Low Impact Velocity
Introduction
Composite materials have been widely used in the aerospace, machinery, shipping, and even the
construction industries due to their mechanical properties like high corrosion resistance, high
strength, high fatigue resistance, large damping, high stiffness and light weight (Matemilola and
Stronge, 2011, p. 2667). This property has made these materials specifically to be applicable in
the aerospace industry (Faggiani and Falzon, 2010, p. 741). Cylindrical composite pressure
vessels are however vulnerable to impact as it causes the material to deform and since they are
pressure vessels result in the vessel bursting at a certain pressure where the impact enhances
crack initiation, propagation and failure. This occurrence is associated with the fact that the
material has a low level of toughness which makes it brittle and thus easy for cracks to be
initiated, and propagated in the event of impact (Gong, Shim, and Toh, 2015, p.257).
Low velocity impact does not cause the crack development to be visible and this works to reduce
the burst strength of the vessel and thus increase the vulnerability of the vessels to accidents
Bursting of the cylindrical composite pressure vessels in the case of low velocity impact occurs
after deformation on the cylinder occurs. This deformation damages the fibers of the hoop layers
of the cylinder as induced compressive stresses which cause buckling whose intensity depends
on the material thickness. Other factors that are known to result in this buckling behavior include
the layup pattern of the hoop layers, the curvature of the material, the impact velocity and
resultant energy, the shape and size of the member impacting the pressure vessel and the
boundary conditions (Changliang, Mingfa, Wei, Haoran, 2016, p. 389).
Objective
This study considers a cylindrical composite pressure vessel that will be impacted on low
velocity using finite element analysis and the ansys software. The study enabled a
comprehension of failure progression to bursting in the material. The analysis will also entail the
evaluation of the burst pressure of the pressure vessel. The finite element method will be used to
conduct the structural assessment of the vessel while ansys will be used to model deformation

and analyze stresses around the point of impact and the mechanics of the damage resulting to
bursting.
Method
In this study, the stress distributions of composite pressure vessel were analyzed for a cylindrical
composite pressure vessel with the following boundary conditions. The internal vessel was made
of high-density polyethylene (HDPE) covered by fiberglass and the inner and the outer diameters
of the vessel are 114.5mm and 152.4 mm respectively. The length of the pressure vessel is 457.2
mm and the fibre orientation angles of the vessel are 90,+45 and -45 degrees
A 16mm hemispherical indentor was used to impact the pressure vessel on low velocity.