{"id":"wpc-tech100-article-063-en","slug":"notches-and-stress-concentrations-in-composite-profiles","locale":"en","url":"https://woodplasticcomposite.net/guides/notches-and-stress-concentrations-in-composite-profiles/","title":"Notches and stress concentrations in composite profiles","answer":"A notch, hole or machined corner can change where a WPC component begins to fail. Unnotched specimen data should not automatically be applied to a detailed connection or cut profile.","author":"NFC & WPC Knowledge Reference","faqIds":["wpc-tech100-faq-063-en"],"tagIds":[],"noindex":false,"related":["wpc-tech100-article-064-en"],"version":1,"modified":"2026-10-15","reviewer":"","sections":[{"id":"technical-context","text":"The local geometry and loading direction influence the stress concentration. Manufacturing damage can add another variable. A smooth laboratory bar may therefore answer a different question from a board with a drilled or routed feature.","heading":"Technical context","references":[],"url":"https://woodplasticcomposite.net/guides/notches-and-stress-concentrations-in-composite-profiles/#technical-context"},{"id":"verification-plan","text":"Test representative details where they are important to the intended use. Record tool condition, hole or notch geometry and edge distances. Distinguish the effect of the design detail from damage introduced during specimen preparation.","heading":"What to measure and document","references":[],"url":"https://woodplasticcomposite.net/guides/notches-and-stress-concentrations-in-composite-profiles/#verification-plan"},{"id":"practical-decision","text":"Do not create universal drilling or routing dimensions from this principle. Use the selected manufacturer's instructions and engineering assessment. A detail is acceptable because the complete arrangement is supported by evidence, not because the base composite has a high nominal strength.","heading":"Implications for development and specification","references":[],"url":"https://woodplasticcomposite.net/guides/notches-and-stress-concentrations-in-composite-profiles/#practical-decision"},{"id":"reading-scope","text":"A finite-element modelling study compared predictions with tests on several WPC products. Use the linked work as related reading. The practical checks above are editorial recommendations, not reported test results or a substitute for product qualification.","heading":"Related reading and evidence limits","references":[1],"url":"https://woodplasticcomposite.net/guides/notches-and-stress-concentrations-in-composite-profiles/#reading-scope"}],"seoTitle":"Notches and stress concentrations in composite profiles | WPC Reference","topicIds":[],"published":"2026-10-15","tableText":"Review step | Evidence to retain\nMaterial and geometry | Exact specimen or product identity\nVerification | Method, conditions and individual observations\nDecision | Approved scope and documented limitations","takeaways":"The local geometry and loading direction influence the stress concentration.\nTest representative details where they are important to the intended use.\nDo not create universal drilling or routing dimensions from this principle.","aiAssisted":true,"categoryId":"wpc-tech100-category-3","reviewedAt":"","change_note":"New focused technical draft; not a product certification or production recipe.","description":"A notch, hole or machined corner can change where a WPC component begins to fail.","heroImageId":"","referenceIds":["wpc-tech100-ref-fem"],"review_status":"AI-assisted English editorial draft. Human technical review has not been recorded.","table_caption":"Evidence checklist for notches and stress concentrations in composite profiles","seoDescription":"A notch, hole or machined corner can change where a WPC component begins to fail.","translationGroup":"wpc-tech100-063-2026","references":[{"url":"https://research.fs.usda.gov/treesearch/53195","type":"web","title":"WPC flexure prediction from axial and shear data","noindex":false,"accessed":"2026-10-14","seoTitle":"WPC flexure prediction from axial and shear data","publisher":"USDA Forest Service","description":"Related reading; scope and limitations are identified in each article.","seoDescription":"Related reading; scope and limitations are identified in each article."}],"faqs":[{"question":"What evidence is needed for notches and stress concentrations in composite profiles?","answer":"Test representative details where they are important to the intended use. Record tool condition, hole or notch geometry and edge distances. Distinguish the effect of the design detail from damage introduced during specimen preparation."}]}