Project Context

This project involved the design and comparative analysis of a multilayer bulletproof vest using composite materials. Multiple material stack-ups were evaluated to balance ballistic impact resistance, thermal comfort, and overall weight using numerical simulations.

Engineering Problem

• Absorb and dissipate kinetic energy from a high-velocity projectile

• Minimize vest mass while maintaining acceptable deformation limits

• Compare composite layer stack-ups for impact resistance and heat dissipation

• Select an optimal configuration using quantitative, multi-criteria evaluation

Approach & Methodology

A scaled bullet and vest geometry were modeled in SOLIDWORKS and assembled as layered composites. Composite stack-ups were defined in ANSYS ACP (Pre) using woven fiber models. Explicit dynamic simulations were performed with a tungsten bullet (0.61 g) impacting the vest at 426–480 m/s to evaluate deformation and kinetic energy absorption. Steady-state thermal analyses were conducted to compute heat flux and temperature gradients across layers. Four material combinations using Kevlar, Graphene, Boron Carbide, Silicon Carbide, and Spectra were simulated and compared.

Key Results

• Vest weights ranged from 55.6 g (Kevlar-based) to 70.1 g (Graphene-based) depending on stack-up

• Bullet kinetic energy reduction across combinations: 45.6–46.2 J

• Minimum inner-layer deformation ranged from 0.105 mm to 0.195 mm

• Average heat flux values varied widely, from ~182 W/m² to ~1.43×10⁵ W/m² depending on material selection

• Average vest temperatures ranged from ~25.1 °C to ~34.8 °C

• Final ranking identified Graphene–Boron Carbide–Spectra stack-up as the optimal configuration based on weighted performance metrics

Engineering Judgment & Trade-offs

Kevlar-based configurations minimized weight but exhibited higher deformation. Graphene-dominated stacks improved deformation control and thermal performance at the cost of increased mass. Ceramic strike-face layers enhanced ballistic resistance but influenced thermal gradients. The final selection balanced impact absorption, deformation, and thermal comfort rather than optimizing a single metric.

Tools & Methods

SOLIDWORKS CAD, ANSYS ACP, ANSYS Explicit Dynamics, ANSYS Thermal, composite laminate modeling.

Outcome / Takeaway

The study demonstrated a structured multiphysics workflow for evaluating ballistic armor concepts. Quantitative comparison across impact, thermal, and weight metrics enabled informed material selection, identifying a graphene-based composite stack as the most effective overall design.