Jäykkyysmoduli

jäykkyysmoduli, also known as shear modulus or rigidity modulus, is a material property that describes its resistance to shear deformation. It is a measure of how much an object deforms when a force is applied parallel to one of its surfaces, while the opposite surface is held fixed. Mathematically, it is defined as the ratio of shear stress to shear strain. Shear stress is the force per unit area applied parallel to the surface, and shear strain is the resulting deformation angle.

The jäykkyysmoduli is an important parameter in engineering and physics, particularly in the design of structures and mechanical components. Materials with a high jäykkyysmoduli are more rigid and resist twisting or shearing forces better. For example, metals generally have higher jäykkyysmoduli than polymers. The unit of jäykkyysmoduli in the International System of Units (SI) is the pascal (Pa), although it is often expressed in gigapascals (GPa) for convenience.

Values for jäykkyysmoduli vary significantly between different materials. For instance, steel has a jäykkyysmoduli of approximately 79 GPa, while aluminum is around 26 GPa. Understanding this property is crucial for predicting how materials will behave under stress and ensuring the structural integrity of various applications, from aircraft wings to bridges. It is a key component in the constitutive equations used in solid mechanics to describe the elastic behavior of materials.