maradványfeszültségek

Maradványfeszültségek, also known as residual stresses, are stresses that remain within a solid material after the original applied load has been removed. These stresses arise from a variety of sources during the manufacturing or processing of materials. They are internal stresses that are present even in the absence of external forces.

Common sources of maradványfeszültségek include plastic deformation, uneven cooling or heating of a material, phase transformations, welding, machining, and shot peening. For example, when a metal is bent beyond its elastic limit, it undergoes plastic deformation, and upon unloading, some internal stresses remain. Similarly, during welding, the rapid heating and cooling of the metal creates temperature gradients that lead to residual stresses.

The presence of maradványfeszültségek can have significant effects on the performance and integrity of a component. Tensile residual stresses can reduce the fatigue life and fracture toughness of a material, making it more susceptible to cracking. Conversely, compressive residual stresses can improve fatigue resistance and inhibit crack propagation. Therefore, understanding and controlling residual stresses is crucial in many engineering applications, such as in aircraft components, pressure vessels, and structural elements.

Various techniques exist to measure maradványfeszültségek, including X-ray diffraction, neutron diffraction, and hole drilling. These methods allow engineers to assess the magnitude and distribution of these internal stresses. In some cases, it may be necessary to intentionally introduce beneficial residual stresses through processes like shot peening or autofrettage to enhance the material's performance. Conversely, undesirable residual stresses can sometimes be reduced or relieved through heat treatment processes.