Aramid fiber (Kevlar 49)
High-stiffness aramid; excellent specific strength and damage tolerance, weak in compression.
Also called: Kevlar 49, aramid fibre, para-aramid, Kevlar
| Property | Value | Source | Method | Conditions | Note |
|---|---|---|---|---|---|
| Density | 1.44 g/cm³ | Daniel & Ishai, Engineering Mechanics of Composite Materials, 2nd ed. | — | 23 °C, dry | — |
| Young's modulus E | 131 GPa | Daniel & Ishai, Engineering Mechanics of Composite Materials, 2nd ed. | — | 23 °C, dry | axial |
| Tensile strength | 3620 MPa | Daniel & Ishai, Engineering Mechanics of Composite Materials, 2nd ed. | — | 23 °C, dry | — |
Kevlar 49 is a high-modulus para-aramid fibre with an exceptional strength-to-weight ratio and outstanding impact, cut and ballistic resistance. It is the reinforcement in body armour, cut-resistant gloves, and impact-critical composite panels.
Its weakness is compression and bending: aramid fibres kink under compressive load, so Kevlar laminates are strong in tension but poor in compression, and are often hybridised with carbon to cover both.
See where Aramid fiber fits in a real product, and what it competes with:
- Daniel & Ishai, Engineering Mechanics of Composite Materials, 2nd ed.
Typical room-temperature values for learning and preliminary design; grades vary. Always confirm against the supplier datasheet before design work. Data policy: docs/DATA-SOURCES.md in the repository.