Mortar shell design is one of the most critical components in defence organization of projectilerndesign. Unavilability of data and literature regarding artillery projectiles and rocket warheads,rnare considered to be one of the main contributors for the failure of manufacturing projectile in arnlocal industry.rnThe need for this study is to design and fabricate this type of mortar shell in Ethiopia itself. Thus,rnthe primary objective of this thesis is to develop a ballistics model of mortar shell and predictingrnthe performance of mortar casing by ANSYS a finite element analysis package. Initially, thernmodel is designed as a simplistic ballistic model capable of predicting the pressure and thrustrngenerated by a propellant from a given set of input parameters. Its structure was determined onrnthe basis of gun design empirical, experimental investigations of ballistic research laboratoriesrn(BRL) and weapon design of ammunition and artilleries of high explosive calibers.rnHigh explosive warhead performances depend on its geometrical shape and dimensions, mass ofrnexplosive charge and explosive type, material of warhead case, initiation way and initiation pointrnposition, fuse type, round to round variations, etc. These are important parameters in determiningrnthe state of projectile features and stresses during the design of projectile. Thus, in this work arnparametric study is conducted by varying the casing thickness and its length to study their effectrnon the fragmentation and stability of mortar projectile for the selected design parameters.rnAnalysis of stresses and deformation in the casing is an important area of research for projectilesrnoptimal design. This thesis investigates the characteristics of high explosives warheadrnfragmentation analysisrnThis research not only gives fragmentation analysis of the shell by continuum method andrntrajectory calculations, but also gives the stress values for three different loading conditionsrncorrespond to launching, hitting the target and subsequent pyro blast.rnTo estimate the structural stress, three-dimensional model of a mortar shell was made by finiternelement method using ANSYS. This thesis also considers the study of variation of primary andrnsecondary propellant charge on range. The results obtained by this research are presented andrncompared with the available literature. This study not only validates the design of the mortarrnshell, but also helps the Defense Ministry go ahead with its production for its need.rnxiiirnObjectives of the thesisrnThe specific objective of this thesis work is to determine structure and shell thickness forrnmaximum fragmentation and to analyze mechanical stress due to different loads acting onrn120mm mortar shell. The objective includes in general terms the following.rnâ€¢ To determine the basic structure of the mortar shellrnâ€¢ To determine the fragmentation, internal ballistic, range and stability of the mortar shellrnâ€¢ To determine the variation of the mechanical stress and deformation across the shell atrnthree positionsrn at the launching caused by propellant gas pressure and temperaturern impact at the instant of hitting the targetrn due to developed explosion pressurernâ€¢ To select the appropriate material and dimension in order to withstand the mechanicalrnstresses before bursting pressurernâ€¢ To determine and analyze the structural performance of the mortar shellrnusing finite element analysis (FEA)rnThese objectives will be achieved by employing the following procedures:rnâ€¢ Designing the structural configurations based on the gun design empirical andrnexperimental standardsrnâ€¢ Warhead fragmentation analysisrnâ€¢ Creating a 3D modeling of the shellrnâ€¢ Develop finite element solution/ANSYS analysis for the problem.rnâ€¢ Analyzing of FEM results in reference of failure criterion.rnâ€¢ Suggesting appropriate design and method of manufacturing.rnxivrnLimitation and Scope of the workrnProjectile design is a process that entails many complicated procedures which involve manyrnaspects of knowledge, experience and interrelationships between disciplines. These decisionsrnwere typically made sequentially by individuals or teams with expertise in various areas of therndesign process. The design process utilizes a combination of hand estimations, predictions fromrnsoftware codes, and physical testing at each phase of the design process, iteratively, in order tornarrive at an optimum configuration. Each discipline involved in the design process has over-timerndeveloped its own set of automated tools. Traditionally, projectile designers used a combinationrnof formulas, charts, and rules of thumb and verified their predictions with experiments. Thesernexperiments included mechanical testing, wind tunnel testing, flight testing and target effectsrntesting of pit fall and arena fragmentation. Measurements of warhead performances require veryrncomplex measuring equipment and measuring process itself is expensive as well. Out of manyrnyears of such experimentation, useful references evolved, such as the Army Design Handbookrnand Pamphlet series, specialized notes, and textbooks. These are not completely ignored inrncontemporary procedures and codes and will be included in this environment. These basicrnmethods and models will be part of the initial (or rough cut) phase estimates in this system.rnDue to unavailability of datas, softwares and test facility, the detail of exterior and intermediaternballistic parts, physical and chemical behaviour of explosives and the effect of fragment with thernbody of human tissue arenâ€™t taking into account in this work.rnIt has been shown that the development of projectile consists of four stages. In the first stage thernbasic structural shape dimension are determined based on the required effect of fragment andrnrange causes the internal mechanical response of the mortar shell inside and outside the barrelrnstructures. The second stage consists of the development of fragmentation analysis. This will berndone using warhead fragmentation analysis. The present work focuses on the first stage: therndetermination of the internal and external mechanical response of mortar casing using finiternelement models.rnThere have been some efforts made to integrate the various areas of projectile design; thernsoftware code ANSYS comes closet to achieving this. Important aspects of these models are:rngeometry, loading that mimic the actual loading conditions and interface conditions with thernbarrel structures. The focus in this study will be on designing , anlysing at each design phasesrnand modeling of mortar shell based on gun design method.rnxvrnOutline of the ThesisrnIn Chapter 1, we give an overview of mortar projectile, system description and literature review.rnChapter 2, Different gun design equations and empirical relations of high explosives are usedrnand a suitable modification to determine the basic structural configuration of the shell at arndesired load level is incorporated. Material properties of fabrics is described. In Chapter 3, thernthickness of the shell is determined from the fragmentation point of view. Intensive Mottâ€™srnequation computations have been performed to search for the best fragment velocity andrnoptimum fragment weight. In Chapter 4, here, the primarily concern of basic internal ballisticsrnare studied to determine muzzle velocity, pressure and charge consequence on range. In Chapterrn5, Aerodynamic moments and forces for two dimensional domains are presented. A method torncompute the static and dynamic stability of a spinning and finned type projectiles is validated. InrnChapter 6, modeling and finite element solutions are presented for three conditions of thernprojectile along its trajectory from launching up to its end effect. In Chapter 7, we drawrnconclusions from this thesis and suggest possible avenues for future work.