Creep behavior of composite cylinders: effects of thermal gradients, reinforcement, and residual stress

This study presents a detailed numerical investigation of creep-induced stress and strain distributions in particle-reinforced composite cylinders under combined internal pressure, thermal gradients, and residual stress using an explicit finite difference method. The model incorporates steady-state creep, radial thermal variation, and reinforcement effects, and was validated against experimental data from previous research. The tangential stress peaks at 1.2 × 10⁵ MPa near mid-thickness (0.08 m), while radial stress increases from 0.05 × 10⁴ MPa at the inner radius to 0.88 × 10⁵ MPa at the outer radius. Strain rates vary from −1 × 10¹⁰ s⁻¹ (tangential) and −3 × 10⁹ s⁻¹ (radial) at the inner radius to 2.3 × 10¹⁰ s⁻¹ and 1.8 × 10¹⁰ s⁻¹ at the outer radius, respectively. The model demonstrates strong validation with <i>R</i>² = 0.99 for radial strain rate and Phi (ϕ), and Mean Absolute Percentage Error (MAPE) values of 3.46% and 4.66% for Phi and radial stress, respectively. Sensitivity analysis reveals that increasing SiC particle volume fraction from 0.05 to 0.25 enhances stiffness and modifies stress distribution, while a 50-K thermal gradient and residual stresses of 1.5 × 10⁵ MPa significantly elevate internal stress levels. This validated framework enables accurate prediction of long-term deformation and supports optimized design of high-performance composite cylinders used in aerospace, nuclear, and energy applications.