Robiul Hossen

Effect of magnesium oxide on mechanical behavior of jute fiber reinforced epoxy bio-nanocomposite

How a small nanoparticle addition rebalances strength, ductility, and interfacial bonding in a waste-derived natural-fiber composite.

Composites were fabricated by hand lay-up from recycled jute fibers with 0, 2, and 4 wt% MgO nanoparticles, then characterized mechanically and chemically. The 2% MgO composite traded a modest drop in tensile strength (30.53 to 25.82 MPa) for markedly higher strain at failure, shifting behavior from brittle to ductile. FTIR peak shifts confirmed Mg–O–C bonding at the fiber-matrix interface, and SEM showed uniform dispersion at 2% but agglomeration and porosity at 4%, identifying an optimal loading threshold.

Optimized Structural Design and Stability Validation of Naval UNREP/RAS Stations: A Finite Element and Stability Integration Study

How finite element analysis and algorithm-driven optimization cut structural weight without crossing the line into unsafe stress or unstable trim.

A naval replenishment-at-sea station was modeled in FEMAP and optimized through genetic algorithms, surrogate modeling, and perturbation load analysis, tuning plate thickness and stiffener arrangement across six load types and multiple testing and failure combinations. The optimization achieved roughly 10% structural weight reduction while peak von Mises stress reached 219.06 MPa, staying within the 220 MPa allowable limit for ASTM A-36 mild steel. Manual stability validation under SOLAS II-1 Regulation 5.4 confirmed the 19,246 kg installation raised lightship displacement by only 0.17%, with VCG and LCG shifts of 0.12% and 0.04%, well inside the 0.5% regulatory limits. The result is a regulation-compliant framework that removes the need for a re-inclination experiment.

Effect of Untreated Jute Fiber Incorporation on the Properties of Recycled Denim–Epoxy Hybrid Composites

Turning textile waste into load-bearing composites — and reading the data honestly when the untreated interface underperforms.

Recycled denim-epoxy and untreated jute-denim hybrid epoxy composites were fabricated by hand lay-up and characterized mechanically, thermally, and morphologically. The recycled denim composite showed superior performance, achieving a tensile strength of 31.4 ± 0.2 MPa and an impact strength of 8.30 ± 0.39 kJ m⁻², whereas adding untreated jute reduced tensile strength to 25.2 ± 0.3 MPa (19.5%) and impact strength to 5.60 ± 0.30 kJ m⁻², indicating inefficient stress transfer. SEM revealed fiber pull-out and interfacial debonding, while TGA/DSC showed comparable thermal stability. Despite lower water absorption and porosity in the hybrid composite, untreated jute acted as a weak interfacial phase, highlighting the need for fiber surface treatment to improve sustainable hybrid composites.