ISO 15024:2023 is an International Standard that defines a method for determining Mode I interlaminar fracture toughness (critical energy release rate, GIC) for unidirectionally reinforced fibre-reinforced plastic composites using a double cantilever beam (DCB) specimen.
If you need help confirming whether ISO 15024 fits your laminate type, data requirements, or program documentation, talk with our team about your testing workflow.
ISO 15024:2023 — Fibre-reinforced plastic composites — Determination of mode I interlaminar fracture toughness, GIC, for unidirectionally reinforced materials
ISO 15024 is used when delamination resistance under opening-mode (Mode I) loading needs to be measured and reported in a consistent way. The standard centers on DCB testing, where a controlled opening load drives a crack along the laminate mid-plane from a starter delamination.
Because interlaminar fracture properties can be sensitive to specimen build, insert/precrack approach, and data-reduction choices, equipment and fixturing should be selected with the specific ISO 15024 edition and the test lab’s reporting expectations in mind.
Quick Definition
What it is: A standardized DCB-based method for measuring Mode I interlaminar fracture toughness (GIC) in unidirectional fibre-reinforced polymer matrix composites.
What you get: A quantitative measure of resistance to delamination initiation and/or propagation under opening-mode loading, reported as critical energy release rate.
What it is not: A product specification or pass/fail procurement requirement by itself; it is a test method used to generate comparable material performance data.
What This Standard Covers
ISO 15024 specifies a procedure for determining Mode I interlaminar fracture toughness for unidirectional fibre-reinforced plastic composite materials using a DCB specimen configuration.
The method is commonly used to characterize delamination behavior associated with laminate design changes, resin/toughener selection, fibre/resin interface performance, and process changes that can influence interlaminar performance.
Why This Standard Matters in Testing
Interlaminar fracture toughness is a key property for understanding and comparing how laminates resist delamination growth. In many composite programs, Mode I delamination metrics are used alongside other mechanical properties to support material screening, qualification, or ongoing process verification.
From a lab-operations standpoint, ISO 15024 helps standardize specimen loading, measurement expectations, and result reporting so GIC values can be compared across batches, suppliers, and development iterations with less ambiguity.
Common Materials, Product Types, or Applications Covered
ISO 15024 is focused on unidirectionally reinforced fibre-reinforced polymer composites. Typical use cases include carbon-fibre and glass-fibre reinforced laminates where delamination performance is a design concern.
Common application areas: Aerospace and defense laminates, wind-energy composites, high-performance sporting goods structures, automotive structural composites, and general R&D programs developing tougher resin systems or interfaces.
Common Test or Verification Workflow
ISO 15024 testing is typically run as a controlled-displacement DCB opening test where load and opening displacement are recorded while the crack advances from a defined starter delamination region.
Common workflow steps: Prepare DCB specimens with a starter delamination feature, attach the required loading hardware (such as hinges or load blocks), run a controlled-displacement opening sequence, track crack length progression with an appropriate measurement approach, and calculate/report GIC values per the standard’s calculation and reporting framework.
Data sensitivity: Results can be strongly influenced by how crack initiation is defined, how crack growth is observed/recorded, and which calculation options are used, so procedures and software templates should align with the cited edition.
Equipment Commonly Used for This Standard
ISO 15024 is equipment-driven: the test requires stable displacement control, aligned loading through DCB-specific hardware, and a practical way to monitor crack growth. In most labs, this points to a universal testing machine configured for composite fracture testing.
Common equipment families: Universal testing machine (electromechanical or servo-hydraulic), suitable load cell, displacement measurement (machine crosshead and/or a dedicated displacement transducer as required by the lab procedure), and DCB loading fixtures/hardware (commonly hinge- or block-based loading arrangements).
Crack-length measurement options: Visual scale and microscope, traveling microscope, or camera/video-based measurement systems, depending on the lab’s accuracy and documentation needs.
Practical selection caution: DCB tests are sensitive to alignment and low-force resolution; ensuring appropriate force-range selection, smooth displacement control, and repeatable hinge/block attachment often matters as much as machine capacity.
How to Read This Designation or Revision
Standard number: ISO 15024 is the base designation for this DCB-based Mode I interlaminar fracture toughness method.
Year and edition: The year (for example, 2023) identifies the publication date of the cited version. ISO 15024:2023 is the current published edition, and ISO 15024:2001 is an earlier edition that has been withdrawn.
Why the edition matters: Equipment setup, permitted loading hardware configurations, calculation/reporting expectations, and referenced requirements can change between editions, so test plans and quotes should always match the exact version stated in your customer or program documentation.
Related Standards, Methods, or Frameworks when useful
ISO 15024 is often used alongside other composite mechanical test methods when building a more complete material property set (tension, compression, shear, and other fracture or delamination-focused methods).
Within ISO 15024 itself, general machine performance expectations for maintaining a constant displacement rate may reference broader plastics testing guidance (for example, requirements aligned with ISO 527-1), so it is important that the test machine control and verification approach supports stable, repeatable displacement-controlled loading.
Get help configuring an ISO 15024 test setup
If you are planning ISO 15024 testing and need help selecting a UTM, DCB hinges/load blocks, crack-length measurement options, or a data acquisition approach that fits your reporting requirements, you can request a detailed quote for an ISO 15024-ready configuration.