Search results
Results from the WOW.Com Content Network
It gives the contact stress as a function of the normal contact force, the radii of curvature of both bodies and the modulus of elasticity of both bodies. Hertzian contact stress forms the foundation for the equations for load bearing capabilities and fatigue life in bearings, gears, and any other bodies where two surfaces are in contact.
Hertz contact stress in the case of a male cylinder-female cylinder contact. When the clearance can not be neglected, it is then necessary to know the value of the half contact angle θ 0, which can not be determined in a simple way and must be measured. When this value is not available, the Hertz contact theory can be used.
Projectiles apply a Hertzian contact stress at the point of impact to a solid body, with compression stresses under the point, but with bending loads a short distance away. Since most materials are weaker in tension than compression, this is the zone where cracks tend to form and grow.
Contact mechanics is the study of the deformation of solids that touch each other at one or more points. [1] [2] This can be divided into compressive and adhesive forces in the direction perpendicular to the interface, and frictional forces in the tangential direction.
Normal contact stiffness is a physical quantity related to the generalized force displacement behavior of rough surfaces in contact with a rigid body or a second similar rough surface. [ 1 ] [ 2 ] Specifically it is the amount of force per unit displacement required to compress an elastic object in the contact region.
The microscopic origin of contact forces is diverse. Normal force is directly a result of Pauli exclusion principle and not a true force per se: Everyday objects do not actually touch each other; rather, contact forces are the result of the interactions of the electrons at or near the surfaces of the objects. [1]
The stress vectors acting on the faces of the tetrahedron are denoted as T (e 1), T (e 2), and T (e 3), and are by definition the components σ ij of the stress tensor σ. This tetrahedron is sometimes called the Cauchy tetrahedron. The equilibrium of forces, i.e. Euler's first law of motion (Newton's second law of motion), gives:
Stress is frequently represented by a lowercase Greek letter sigma (σ). [3] Strain inside a material may arise by various mechanisms, such as stress as applied by external forces to the bulk material (like gravity) or to its surface (like contact forces, external pressure, or friction).