Overview
EN ISO 26203-2:2011 - "Metallic materials - Tensile testing at high strain rates - Part 2: Servo-hydraulic and other test systems" (CEN adoption of ISO 26203-2:2011) specifies requirements for performing reliable high-rate tensile tests on metallic materials. The standard covers dynamic tensile testing primarily using servo-hydraulic test systems (unless otherwise specified), with example geometries for flat specimens. Applicable strain rates range from 10−2 s−1 to 10^3 s−1, and tests are conducted at 10 °C to 35 °C. The document defines apparatus, specimen geometry, measurement, data acquisition, evaluation and reporting needed to produce valid stress–strain and flow curves for dynamic material characterization.
Key topics and technical requirements
- Scope and strain-rate range: Test procedures for strain rates from 0.01 s−1 up to 1000 s−1 for metallic materials; quasi-static tests below 10−2 s−1 are covered elsewhere.
- Apparatus: Preferred use of servo-hydraulic drives (frequently with slack adapters); other systems (flywheel impactors, drop towers) permitted if requirements are met.
- Specimen geometry & preparation: Examples focus on flat tensile specimens for sheet materials; other geometries may be used following referenced guidance.
- Force and extension measurement: High-rate requirements for load cell placement, extensometer gauge length, and measurement bandwidth to ensure force equilibrium and accurate strain data.
- Data acquisition: High sampling rates and defined upper frequency limits to capture rapid events and calculate time-dependent engineering strain rates.
- Evaluation: Procedures for deriving stress–strain curves, determining key values (yield, proof, tensile strength), mean and time-dependent strain rates, and flow curves.
- Alignment & load train design: Emphasis on axial symmetry and compact load trains to minimize bending and raise natural frequencies.
- Test report: Prescribed information to ensure traceability and reproducibility (machine type, specimen geometry, strain rate, temperature, measurement methods, data processing).
Applications and users
EN ISO 26203-2 is essential for:
- Automotive and aerospace engineers requiring dynamic material properties for crashworthiness and impact simulations.
- Materials scientists and R&D labs performing high-rate tensile testing for alloy development.
- Mechanical testing laboratories, quality assurance teams, and simulation/modeling engineers who need validated stress–strain data at elevated strain rates for finite-element analysis.
- Defense and safety industries where impact loading characterization is critical.
Keywords: tensile testing at high strain rates, servo-hydraulic test systems, metallic materials, dynamic tensile tests, ISO 26203-2:2011, high-rate tensile testing standard, stress–strain curve, flow curve.
Related standards
- ISO 26203-1 - Part 1: Elastic-bar-type systems (complements Part 2)
- ISO 6892-1 - Tensile testing at room temperature (quasi-static methods)
- ASTM E1012 - Alignment of testing machines (referenced for load train alignment)