Jäännöspaineita

Jäännöspaineita, known in English as residual stress, refers to stresses that remain within a solid material after the original applied load has been removed. These internal stresses can exist without any external forces acting on the object. Residual stresses are a result of manufacturing processes or service conditions, such as welding, machining, heat treatment, plastic deformation, or uneven cooling.

The presence of residual stresses can have a significant impact on a material's mechanical properties. Tensile residual stresses can decrease the material's fatigue life and fracture toughness, making it more susceptible to cracking. Conversely, compressive residual stresses can enhance these properties by counteracting applied tensile stresses, thereby increasing resistance to fatigue and crack propagation.

Understanding and controlling residual stresses is crucial in many engineering applications. Techniques to measure residual stresses include X-ray diffraction, neutron diffraction, and hole drilling. Methods to induce beneficial residual stresses often involve controlled processes like shot peening or laser peening, which introduce compressive stresses on the surface. Managing residual stresses is vital for ensuring the safety, reliability, and longevity of components and structures across various industries, including aerospace, automotive, and civil engineering.