NUMERICAL AND EXPERIMENTAL RESPONSE ANALYSIS OF DAMAGE MODES OF COMPOSITE PLATES SUBJECTED TO EXPLOSIVE LOADING

• Main Author: Gunaryo
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/54097
• Institution: Institut Teknologi Bandung

The crime of terrorism is similar to using explosives to carry out terror, and the number of victims continue to increase from year to year. In fact, terrorism is a threat to all parties, hence efforts are needed to reduce the negative impact of an explosion. Therefore, the use of protective structures can be applied to building and vehicle construction. Composite material is one of the protective structures that can be used to reduce the impact of an explosion, and those that are generally used are glass and carbon. Therefore, it is important to study the behavior of composite plates under an explosion load that results in a combination of explosive waves and fragments. It is also very necessary to study the characteristics of the damage. The test activities using TNT and shelled TNT (Grenade GT-50) explosives can represent the source of explosions commonly used in war and terror. Furthermore, the standard for determining the strength of composite materials comes from STANAG level 1 with categories according to EN1063. Glass fiber composite plates are produced using a hand layup vacuum technique and heated in an oven. Meanwhile, carbon fiber composite plates are the material used in the fighter development program produced by the pepreg system at PT DI. The composite material area for the test that measures 25 x 25 mm is the optimal area to receive a TNT blast load of different masses of 60 g, 80 g and 100 g. Furthermore, the stand-off distance varies from 300 mm to 1000 mm. Pin pads are placed under the plates to record the maximum composite deflection during both TNT and grenade explosions. Also, LS-DYNA simulation is used for numerical analysis by modeling the composite plate as a shell element using MAT54 and Chang-Chang failure criteria. The TNT's explosives are modeled in two different ways, and the first simulation is modeled using CONWEP. Furthermore, the second is modeled using Smooth particle hydrodynamic (SPH), and grenades are only modeled using SPH. TNT's explosive waves will cause deflection on the composite plate, while hand grenades tend to generate explosive waves and fragments, as well as cause damage to the composite plate. Meanwhile, the numerical analysis of the SPH Model gives better results than the CONWEP method. The SPH results were in the range of 10% compared to the experiment data, while the CONWEP results were in the range of 30%. There are three types of damage caused by hand grenade explosions, which are invisibility, trapped projectile, and wound. Also, the resistance of 25 layers (8 mm) in carbon fiber composites is comparable to a glass fiber composite of at least 50 layers (10 mm). With this linear relationship, designers can easily determine the number of layers according to predetermined requirements (STANAG Level 1). Therefore, it can be used as a basis for making composite plates used as a protective structure. The results of this study have a major impact on the military industry and composite material providers. This is because it can be used to design glass and carbon fiber composite plates as explosion protection materials. In addition, the composite material industry can use the results of numerical calculations without having to test each design