At a glance
Strength describes resistance to a defined failure condition; stiffness describes resistance to deformation. A strong small specimen does not automatically establish a suitable structural profile.
Translate the terminology #
Tensile tests load a specimen in tension. Flexural tests bend it. MOR commonly denotes modulus of rupture, a bending-strength measure, while MOE denotes modulus of elasticity, a stiffness measure. Compression describes another loading condition. Impact tests such as Izod and Charpy introduce their own specimen and loading arrangements.
See the comparison table below for translate the terminology.
Do not merge impact numbers #
Wood/PP research found different particle-size trends for notched and unnotched impact. This illustrates why impact results require their exact test description. An instrumented-impact study of kenaf/PP provides another example of investigating impact behaviour in a specific composite system. [R20,R48]
Specify the evidence chain #
The EN 15534 family connects compound and product characterization with particular end uses. Its existence does not mean that citing the standard number proves compliance.
For a public walkway, request the tested board identity, support arrangement and relevant acceptance criteria. For a new compound, request the number of specimens and variability as well as the mean. Keep initial laboratory properties separate from conditioned values and design values.
This approach lets architects compare products on evidence rather than a single impressive number selected from a datasheet.
Evidence and source scope #
[1] Official standards catalogue; scopes, not full normative text.
[2] Experimental study; official abstract.
[3] Experimental study.
Similar property names can conceal materially different test conditions.
| Reported property | Essential comparison detail |
|---|---|
| Tensile strength | Specimen geometry, direction and conditioning |
| Flexural strength or MOR | Span, section and test procedure |
| Flexural modulus or MOE | Calculation method and conditions |
| Impact result | Test type, notch and units |
Sources & further reading
- EN 15534 standards series; BSI ↗landingpage.bsigroup.com · web · 2026-10-15
- Effects of wood fiber characteristics on mechanical properties of wood/polypropylene composites; Stark and Rowlands ↗research.fs.usda.gov · web · 2026-10-15
- Instrumented Impact Testing of Kenaf Fiber Reinforced Polypropylene Composites ↗research.fs.usda.gov · web · 2026-10-15
Cite this page
J. A. Gill. “Reading WPC mechanical data: strength, stiffness and impact” Version 1. Updated 2026-10-17. https://woodplasticcomposite.net/guides/wpc-mechanical-properties-strength-modulus-impact/
Author profile
Author: J. A. Gill
WPC and natural-fibre composite specialist · Innovator, inventor, product designer and entrepreneur
Converted from the referenced English foundations collection. General technical information and editorial specification guidance; not product certification.
General material information is not product certification or project-specific engineering advice.
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