Composite marine structures are crucial for maritime and aerospace applications due to their strength-to-weight ratio and corrosion resistance. To ensure their reliability and durability, a methodology to predict the damage criticality and service life of composite marine T-joints is essential. Finite Element Analysis (FEA) has emerged as a powerful tool for preliminary design and structural evaluation of complex structures, reducing the need for extensive experimental work and leading to substantial cost savings. This research project aims to conduct a comprehensive FEA of composite T-joints, considering alternative skin, core, and infill materials. Structural analyses under various loading conditions will evaluate overall deflection and stress levels, aiming to enhance the design and reliability of composite marine constructions, ultimately improving their performance and extending their service life in demanding maritime and aerospace environments.

Nowadays, composites made of plant-based fibers may be used to polymer resin synthetic fiber reinforced composites since they are less expensive, renewable, abundant, less abrasive, and lightweight. Echinatus fiber obtained from the stem of the echinatus plant in an abundant amount. The main objective of this study was to develop echinatus polyester-resin fiber reinforced composite material and investigate its flexural strength, hardness and tensile strength. Echinatus plant was collected and echinatus fiber was extracted by the decortication process from the echinatus plants manually, and treated with 5% NaOH for the improvement of bond and interfacial shear strength. And then, the test specimens were manufactured using a mass fraction with 0 , 45 and 90 orientations using technique of hand lay-up. The tensile strength, hardness, and flexural strength were investigated using samples that were prepared according to the ASTM standards. 70% echinatus fiber to 30% polyester composite material with 0 orientation was found as the material with maximum tensile strength of 60.60 MPa, flexural strength of 96.8 MPa, and hardness values of 44.54 HRA. Considering the mechanical properties’ experimental results, echinatus fiber-reinforced composite with 70% fiber at 0 orientation can be good substitutes for synthetic materials.