Overview
ISO/TR 13086-4:2024 - Gas cylinders - Guidance for design of composite cylinders - Part 4: Cyclic fatigue of fibres and liners - is a Technical Report that provides a practical, introductory-level explanation of cyclic fatigue mechanisms affecting structural reinforcing fibres and liners in composite gas cylinders. The report helps designers, manufacturers and test laboratories understand how service conditions, materials and construction influence fatigue life and informs design choices and qualification strategies for composite cylinders.
Key topics and technical content
- Scope and background: Covers common reinforcement (glass, carbon, aramid) and liner materials (steel, aluminium alloys, polymers such as HDPE and polyamide) and their roles in composite cylinder performance.
- Service conditions: Discusses temperature ranges (commonly −40 °C to +85 °C, sometimes lower), moisture effects, pressure ranges (liquified gas ~5–20 bar; high-pressure up to 1 100 bar) and real-world exposure (outdoor, vehicle, stationary).
- Pressure cycling: Guidance on expected pressure cycles and qualification examples (e.g., non‑limited life tests such as 12 000 cycles to test pressure or 24 000 cycles to maximum developed pressure; limited-life examples of 250 or 500 cycles per year per design life).
- Material fatigue behaviour: Discussion of fibre, liner and resin fatigue properties, hybrid constructions, localized strain differences and environmental aging effects.
- Design and analysis elements: Composite/liner load sharing, autofrettage effects (to improve fatigue life), analysis methods, leak-before-burst (LBB) concepts, damage tolerance, cycle counting and combining different types of cycles.
- Testing and qualification: Practical considerations for test specimens, test conditions, and qualification testing strategies to demonstrate acceptable fatigue performance.
Practical applications and users
Who benefits:
- Cylinder designers and engineers specifying composite reinforcement, liner material and winding/layup strategies.
- Manufacturers implementing production processes (including autofrettage and welding practices) to meet fatigue requirements.
- Test laboratories and certification bodies developing qualification programs and interpreting cycle-counting results.
- Material suppliers (fibres, resins, liners) needing to characterize fatigue data under service conditions.
- Fleet operators, gas suppliers and regulators assessing expected service life, maintenance intervals and safety margins for gas cylinders in transport, stationary and vehicle fuel applications.
Related standards and references
- Part of the ISO 13086 series (see ISO website for other parts).
- Terminology cross-reference: ISO 10286 (terms for gas cylinders).
- The report is informative (technical guidance) and not normative; use it alongside applicable regulatory and product standards.
Keywords: ISO/TR 13086-4:2024, composite cylinders, cyclic fatigue, fibres, liners, gas cylinders, cylinder design, qualification testing.