Munition articles may be sensitive to case-crushing loading. This is a potential safety hazard since it may lead to accidental detonation. A better understanding of the mechanism causing the munition articles to react can help improve safety. A finite element model combined with post-processing is used to model a Steven test. This thesis specifically looks at the absence or occurrence of a self-sustaining reaction in energetic material PBX-9501, a polymer bonded HMX based explosive. A reference paper (Gruau et al., 2009) was used to model the behaviour and validate some of the results.
The PBX is predicted to react if it has satisfied a certain reaction criterion based on the hot spot theory of ignition. This theory poses that known chemical properties of the material, the plastic shear strain rate and the hydrostatic pressure can predict the occurrence of a reaction. A finite element model was used to find the plastic strain rate and hydrostatic pressure in the energetic material subjected to a case-crushing loading. Next, the reaction criterion is computed in a separate script. The energetic material was modelled as a homogeneous continuum with a Drucker-Prager yield criterion. This material model did not include any post-yielding behaviour, like strain hardening.
First, a finite element model was constructed that was used as the baseline model throughout the thesis. The combined FEM and post-processing model was shown to be more sensitive than the model in the reference paper. The combined model also predicted a reaction at a lower velocity, which, according to tests in the reference paper, should have not produced a reaction.
The baseline model, and consequent models in the parameter study, also showed excessive deformation. This can be attributed to the use of a simpler Drucker-Prager material model for the PBX as opposed to a more complex material model. The absence of any hardening behaviour, and the resulting deformation, also contributed to the instability of the finite element model.
A parameter study was conducted by adapting the baseline model. Varying the velocity of the projectile was the most impactful change.
In conclusion: the developed model gives a first indication of parameters that contribute to the sensitivity of certain munition articles to case crushing. However, the material model used should be improved to create a more stable finite element model. An improved material model could also better capture the mechanical behaviour of the complex energetic material. It is recommended that future research should focus on this improvement.

Armour systems for ballistic protection can be made from many materials. One type of material used in armour systems is ceramic. Ceramic materials, such as alumina and silicon carbide, can be beneficial in an armour system because of their high hardness and relatively low weight. The high hardness of the ceramic potentially causes a projectile to deform heavily and fracture upon impact with the armour, thereby reducing or even eliminating the threat. The ceramic itself may also damage during the interaction. Although ceramics can damage under impact, they contribute to the protective capability of the armour system as long as they exert a force on the projectile to deformand deceleration it. In order to improve an armour system one does not only need to know when the ceramic component fails, but also how it fails. Once the failure mechanisms of the ceramic are known the armour design may be modified to delay or in an ideal scenario even prevent catastrophic failure of the ceramic. This will eventually result in stronger and lighter armour systems.

Research in this thesis is aimed at comprehensively characterizing the mechanical performance of adobe components. Adobe is a traditional masonry made of sundried bricks and mortar. Bricks are made of soil mixed with fibres and joined together by mud mortar. Adobe is largely spread in areas of the world prone to seismic risk or involved in military conflicts. Its low environmental impact attracts scientific attention also for sustainable applications in current building industry. Unfortunately, the material and structural properties of adobe are still hardly assessed, as a result of centuries of progressive abandonment of this building technology in western countries after introduction of modern building materials in the market. In this doctoral research, a combined experimental and numerical approach was followed. It has been aimed at fulfilling experimental data and knowledge gaps in the study of the main properties of this material. Experimental tests have been performed on bricks and mortar characterized by different mineralogical compositions, fibre percentages and moisture content. Mechanical tests consisted of bending and compression tests. Tests in compression have been performed at different rates of deformation from statics to high velocity impact. Data derived from tests have constituted a solid dataset aimed at interpreting and modelling the mechanical performance of adobe. Experimental trends resulted in physical theories concerning the main features of the quasi brittle response of adobe. In particular, the role of fibres and water content in the mixture on the mechanical response of adobe bricks and mortar has been addressed in this study in the static and dynamic regimes of the spectrum of strain rate induced loadings. The main mechanical parameters in compression and tension for adobe have been statistically determined from the static and dynamic tests. Mechanical properties and physical theories have been framed in several models that interpret the response of adobe for different applications. Constitutive models have been derived to address the uniaxial response in compression at different strain rates of adobes of different mineralogical composition and water contents. A finite element damage model has been developed to simulate the main failure modes specifically observed in earthen bricks at different loading conditions and rates, including high velocity impacts. The numerical study has been devoted at ensuring objectivity of analysis to the results of simulations performed using different mesh refinements of the geometrical model of the tested brick. Furthermore, engineering ballistic models that address the response of adobe walls to small caliber penetrations have been developed in this doctoral research. This thesis contains the description of the performed experiments, the analysis of data, the theoretical interpretations and the models developed for the material characterization of adobe masonry.

In an accidental explosion of ammunition magazine, concrete debris throw hazard is a major safety concern. The current approach to collect explosively-damaged debris after test does not yield representative test data on debris launch condition. This research is initiated to study the possibilities of using polymeric foam material to soft-catch concrete debris, without inducing additional damage. Preliminary design of the soft-catcher are first performed using a modified analytical shock wave model. Numerical analyses using LS-DYNA are subsequently carried out to verify the analytical model assumptions and account the effect of rigid end backing of the soft-catcher. Following then, the debris penetration problem is escalated into 2-D space domain, in order to include the influence of tearing resistances within the soft-catcher. The observed phenomena are eventually translated into design parameters for the soft-catcher.