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This study presents the results of a numerical analysis of the response of Domex 700 and Dormex 1100 steel plates with varying geometries, combined with several different parameters such as a thickness of up to 6 mm and a trinitrotoluene (TNT) mass. Using ABAQUS software, finite-element analysis was run to examine the structural response ability of the steel plates to explosions. In terms of deformation and energy dissipation, the results showed a large differentiation. A sensitivity analysis was used to examine each simulation result in terms of the structural response performance to explosions and identify the variables that had the greatest impact on variations in the thickness, material, geometry, and TNT mass. The best numerical simulation results were found using the multi-attribute decision-making (MADM) approach. Annotations are utilized to assist in identifying the various modifications made during testing. Annotations LXXI to LVIII achieved the lowest value of 6.176 × 10−09, signifying the best results according to calculations made using the MADM approach. This is evidenced by the structural events, demonstrating that the deformation, von Mises stress, and energy dissipation in the circular plate structure were not significantly impacted by the explosion. The variables that most significantly affect variations in deformation, von Mises stress, and dissipated energy – variables that significantly impact the structural response to explosions – are identified through the sensitivity analysis approach. The results of this research can be used to optimize the structural response performance of circular plates.

This review presents various types of epoxy resins and curing agents commonly used as composite matrices. A brief review of cross-linking formation and the process of degradation or decomposition of epoxy resins by pyrolysis and solvolysis is also discussed. Mechanical engineers are given a brief overview of the types of epoxy resin, which are often applied as composite matrices considering that they currently play a large role in the research, design, manufacturing, and recycling of these materials.

Nozzle hole diameter of 3D printer (3DP) can be varied to obtain required product quality as well as to reduce manufacturing times. The use of larger diameter may accelerate manufacturing times of products, yet the product quality, including the mechanical properties, still needs to be investigated profoundly. The purpose of this work is to investigate experimentally the effect of nozzle hole diameter of 3DP to the surface quality, accuracy, and the strength of the product. The specimens were manufactured by fused deposition modelling (FDM) 3D printing using polylactic acid (PLA) as the filaments.Bed temperature, extruder temperature and printing speed were set to be 60∘C, 200∘C and 80 mm/s respectively. The thickness of each layer was set at the ratio of 20% to the nozzle hole diameter. Infill pattern was determined by using line type of 100%. Nozzle hole diameter of 0.3, 0.4, 0.5 and 0.6mmwas compared in thiswork. The results show that bigger nozzle hole diameter enhanced the density and tensile strength of the products thought it was not linearly correlation.

Thermosetting epoxy resin polymer with cycloaliphatic amines curing agent has been widely used for a composite matrix with carbon fiber reinforcement. The utilization was increased due to the superior performance of this epoxy resin compared to other polymers. However, a changing operational environment has potentially reduced composite performance, which most likely begins with matrix degradation. This research applies thermal treatment by the quenching process sequence to the epoxy resin matrix and its reinforced carbon fiber composite (CFRP). The composite is made by epoxy resin diglycidyl ether bisphenol-A, curing with cycloaliphatic amine as matrix and strengthening carbon fiber mat/woven. Three times quenching treatment was performed by heating the specimen around the glass transition temperature and then dipped immediately in fresh water. After quenching treatment, the epoxy resin shows a reduction in tensile strength and elongation. Under infrared observation, epoxy resin does not significantly show changes in functional groups. Investigation under X-ray refraction also indicates no difference in a crystalline structure; this epoxy resin stays in an amorphous form before and after quenching. In contrast to the matrix, the quenching treatment of the CFRP composite above the epoxy resin s glass transition temperature revealed an increase in the interlaminar shear strength (ILSS). The matrix ductility reduction after quenching should be carefully considered for application in the form of epoxy resin sheets or CFRP composite construction materials.

The research presented in this article consisted of analysis of the ship structural accidents at low temperatures and the effect of carbon percentage in various classifications of carbon steel, compared to the high tensile strength steel materials. The objective of this research was to fill the knowledge gap by expanding the understanding of the influence of low temperature, material, and structure on the axial compression test of tubes. The simulations as idealization of the compression test were conducted with variations in temperature, material carbon percentage, and geometry shape, using Finite Element Analysis (FEA). The results showed that at -100 °C, the material had the best ability to resist compression energy; high carbon steel had the highest strength at various carbon percentages, and the square geometry showed the best ability to absorb energy before failure. [ABSTRACT FROM AUTHOR]