International Conference on Manufacturing and Materials Processing (ICMM 2006), Kuala Lumpur, Malaysia, 2006, pp. 363-368. Composite LPG Cylinders as an Alternative to Steel Cylinders: Finite Element Approach Naser S. Al-Huniti * and Osama M. Al-Habahbeh *Mechanical Engineering Department, University of Jordan Amman 11942 – JORDAN E-mail: alhuniti@ju.edu.jo ABSTRACT A finite element analysis is performed using ANSYS software to investigate the prospect of utilizing composite pressure vessels (CPVs) to store and transpose liquefied petroleum gas (LPG) instead of steel vessels. A finite element model that is identical to the actual steel LPG vessel used in the local market is constructed. Composite (cross-ply) and steel are used for the vessel materials for comparison purposes. Different types of loads are applied to both models in an identical manner and their performances are compared. Loading types include internal pressure, axial load, storing radial load, and dynamic impact load. It is found that for the same geometry and loading, the composite pressure vessel has lower stress and higher deflection than the steel vessel. KEYWORDS: Composite, LPG, Cylinder, Finite Element INTRODUCTION Composite materials in general offer a high potential for manufacturing of structures featuring an interesting mechanical performance, mainly with regard to specific stiffness, specific strength, damage tolerance, and energy absorption capability. Composite pressure vessels are a perfect example of the advantages that fiber- reinforced composite materials can offer. They are constructed from strong fibers in combination with a resin or plastic. The process for producing the composite pressure vessel is called filament winding. Composite pressure vessels were originally developed for aerospace applications. Nowadays, such vessels are used in a wide variety of applications such as water treatment stations and petroleum industry. The current state of the art composite pressure vessels are light, safe, but unfortunately rather expensive compared to steel vessels. This is one of the main reasons why a broad introduction of composite vessels for liquefied petroleum gas (LPG) storage and transportation has not taken place yet. Several investigations concerned with the application of composite pressure vessels in different fields have been published. A number of investigators studied the effect of filament winding technology and parameters on the performance of composite pressure vessels such as Shen [1], Cohen et. al. [2], Koussios et. al. [3], and others. A number of publications with a concentration on the finite element technique as a method of analysis of composite pressure vessels were published such as Mackerle [4], Kabir [5], Gramoll [6], Sun et. al. [7], Yousefpour and Nejhad [8], and Mirza et. al. [9]. A more detailed description of the above literature and many others can be found in the review by Al-Habahbeh and Al-Huniti [10]. The purpose of this work is primarily to perform finite element analysis of a composite pressure vessel under different loads and to investigate the possibility of replacing current LPG steel vessels with CPVs. The analysis is carried out using the finite element software package (ANSYS). To the best of our knowledge, no specific study concerning composite LPG vessels similar to domestic steel vessels has been done yet. THE MODEL The model used in this study is shown in figure 1 (a). It is identical in dimensions and shape to the steel LPG vessel used in the local market. The overall height is 643 mm, the height of the cylindrical part is 310 mm, the inner diameter is 300 mm and the thickness is 3 mm. The two torispherical caps are of 109 mm height each. The volume capacity is 26.2 liter. The foot- ring is of 300 mm diameter and 70 mm height, and the handle is of 160 mm diameter and 100mm height.