Overview
ISO/TR 21141:2022 provides a technical framework for the determination of yield and ultimate characteristics and ductility from test data for timber connections and assemblies. Developed by ISO Technical Committee 165, this technical report reviews and consolidates evaluation methods from leading standards in Europe, North America, and Far East Asia. Its primary aim is to clarify similarities and differences across regions to help unify how mechanical properties of timber joints and assemblies are assessed. The parameters described in this document are foundational for evaluating aspects such as the seismic performance of timber structures, focusing on the behavior of individual connections rather than the structural system as a whole.
Key Topics
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Yield and Ultimate Characteristics:
- Methods to determine yield point, yield load, and yield displacement for timber joints and assemblies.
- Procedures for assessing the ultimate (failure) load and displacement.
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Ductility Assessment:
- Approaches to measure the ability of connections and assemblies to undergo large deformations without significant strength loss.
- Calculation methods for ductility factor, including equivalent energy models.
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Envelope Curves:
- Generation and use of load-displacement envelope curves in reversed cyclic and quasi-static tests.
- Methods to deal with symmetric and asymmetric load responses.
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Comparison of International Methods:
- Analysis of different standards (such as EN 12512, ASTM D5652, JIS A1414-2) for yield and ductility assessment.
- Identification of convergences and differences to promote a standardized approach.
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Mechanical Property Testing:
- Guidelines for setting up, executing, and interpreting mechanical tests on timber connections.
- Clarification of terminology and standardized definitions for key mechanical parameters.
Applications
Related Standards
- EN 12512 - Test methods for joints made with mechanical fasteners in timber structures.
- ASTM D5652 - Standard test method for single-bolt connections in wood.
- JIS A1414-2 - Test methods for timber shear wall performance in Japan.
- ISO 6891 - General testing methods for mechanical properties of timber.
- ISO 16670 / ISO 21581 - Standards covering cyclic and static testing of timber connections.
Practical Value
Implementing the guidance of ISO/TR 21141:2022 ensures consistency in the assessment of timber joints’ mechanical characteristics worldwide. By providing a comparative review of major international standards, it enables engineers, researchers, and product developers to align testing and evaluation procedures, ultimately improving the safety, reliability, and global acceptance of timber structures. This improved standardization is particularly valuable for advancing timber engineering in areas prone to seismic activity, where accurate measurement of ductility and energy dissipation is critical.
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