# Multi-Objective Optimization of the Dry Towpreg Filament Winding Process for Carbon/Epoxy Type IV Hydrogen Storage Vessels

## TL;DR

This paper optimizes the dry filament winding process for hydrogen storage vessels to improve efficiency and performance.

## Contribution

A novel multi-objective optimization approach combining RSM, NSGA-II, and TOPSIS is applied to enhance dry filament winding parameters.

## Key findings

- Optimal parameters achieved 2462.2 MPa tensile strength and 64.4 MPa shear strength with low prediction errors.
- Dry-wound vessels showed 15.4% lower mass and 17% higher hydrogen storage efficiency compared to wet-wound vessels.
- Heating temperature mainly affects shear strength, while winding tension governs tensile strength.

## Abstract

Hydrogen storage vessels are critical components in hydrogen energy systems, and improving their manufacturing efficiency and structural performance is essential for next-generation Type IV vessel designs. Compared with conventional wet filament winding, towpreg dry filament winding offers higher efficiency, reduced environmental impact, and better adaptability to complex structures. In this study, key process parameters, including winding tension, heating temperature, and winding speed were systematically optimized using the tensile strength and interlaminar shear strength of NOL ring specimens as evaluation metrics. A response surface methodology (RSM) regression model was established to correlate process variables with mechanical properties, followed by multi-objective optimization using the non-dominated sorting genetic algorithm II (NSGA-II) and final parameter selection through the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method. The results indicate that shear strength is primarily affected by heating temperature, whereas tensile strength is mainly governed by winding tension. The optimal parameter combination (79 N, 360 °C, and 11 m/min) yielded tensile and shear strengths of 2462.2 MPa and 64.4 MPa, respectively, with prediction errors below 0.5%. A 9 L Type IV hydrogen storage vessel manufactured under these conditions showed approximately 15.4% lower mass and about 17% higher gravimetric hydrogen storage efficiency than a comparable wet wound vessel.