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The poisson endpoint works with Poisson's ratio ν: the lateral strain that accompanies an axial strain, and the shear modulus G = E/(2(1+ν)) and bulk modulus K = E/(3(1−2ν)) derived from the Young's modulus. Everything is computed locally and deterministically, so it is instant and private. Ideal for mechanical, civil and materials-engineering tools, structural and machine-design apps, materials testing and education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is axial material deformation; for the 2D state of stress (principal stresses, Mohr's circle) use a Mohr-circle API and for column buckling use a buckling API.","contact":{"name":"PremiumApi","url":"https://www.oanor.com/by/premiumapi"}},"servers":[{"url":"https://api.oanor.com/youngmodulus-api","description":"oanor gateway"}],"tags":[{"name":"Elasticity"},{"name":"Meta"}],"components":{"securitySchemes":{"oanorKey":{"type":"apiKey","in":"header","name":"x-oanor-key","description":"Get your key at https://www.oanor.com/developer/keys"}}},"security":[{"oanorKey":[]}],"paths":{"/v1/elongation":{"get":{"operationId":"get_v1_elongation","tags":["Elasticity"],"summary":"Bar elongation under axial load","description":"","parameters":[{"name":"force","in":"query","required":true,"description":"Axial force F (N)","schema":{"type":"string"},"example":"10000"},{"name":"length","in":"query","required":true,"description":"Length L (m)","schema":{"type":"string"},"example":"2"},{"name":"area","in":"query","required":false,"description":"Area A (m²)","schema":{"type":"string"},"example":"0.001"},{"name":"diameter","in":"query","required":false,"description":"Or diameter (m)","schema":{"type":"string"}},{"name":"material","in":"query","required":false,"description":"Material for E","schema":{"type":"string"},"example":"steel"},{"name":"youngs_modulus_gpa","in":"query","required":false,"description":"Or Young's modulus (GPa)","schema":{"type":"string"}}],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"strain":5.0e-5,"area_m2":0.001,"force_n":10000,"formula":"δ = F·L/(A·E); 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