Overview
EN ISO 11343:2019 (ISO 11343:2019) specifies the wedge impact method for determining the dynamic resistance to cleavage of high‑strength adhesive bonds under impact loading. The standard describes how to measure the force or energy required to initiate and propagate a cleavage (peel) crack when a hardened‑steel wedge is driven between two adherends. It applies to common industrial substrates such as sheet metal and fibre‑reinforced plastics, often used in automotive applications. This test standard is for characterization and comparison; it does not provide design rules.
Key topics and technical requirements
- Scope and purpose: Dynamic impact method to quantify cleavage resistance (force per unit width and energy).
- Measured quantities and definitions: dynamic resistance to cleavage (kN/m), cracking force, cleavage force, average cleavage force (measured between the first 25% and last 10% of the plateau), and dynamic cleavage energy (J).
- Apparatus:
- Instrumented impact‑testing machine (pendulum, falling‑weight or servohydraulic). Minimum capability: ≥ 50 J impact energy and ≥ 2 m/s impact speed.
- Instrumentation to record force vs time or displacement with response time at least an order of magnitude faster than the impact event.
- Hardened‑steel wedge (symmetric or asymmetric); wedge geometry and edge radius affect crack progression.
- Wedge support frame (assembly mass specified as 820 g ± 5 g) and specimen clamping with provision for an 8 mm predrilled bolt hole.
- Specimen preparation:
- Two adherends bonded per adhesive manufacturer's instructions or EN 13887 surface‑preparation guidance.
- Substrate thickness representative of industrial practice; controlled adhesive application and consistent surface treatment.
- Data and results: Results expressed as force (N) or energy (J); machines differ in available data (force‑time vs force‑displacement). Note on signal filtering and precision is included.
Practical applications
- Quality control and batch comparison of structural adhesives.
- R&D screening when evaluating adhesive formulations or surface treatments for impact resistance.
- Material selection for industries where impact cleavage is critical - notably automotive, rail, aerospace and structural composites.
- Failure‑mode analysis (cleavage vs cohesive failures) using standardized specimen and reporting.
Who should use this standard
- Adhesive manufacturers and formulators
- Automotive and composite component designers and engineers
- Materials testing laboratories and OEM qualification teams
- Quality assurance specialists responsible for adhesive bond performance under impact
Related standards
- ISO 291 (conditioning/testing atmospheres)
- ISO 10365 (failure pattern designation)
- EN 13887 (surface preparation for adhesives)
Keywords: EN ISO 11343:2019, ISO 11343, wedge impact, adhesives, dynamic resistance to cleavage, high‑strength adhesive bonds, impact testing, cleavage energy, automotive adhesive testing.
