Search results
Results From The WOW.Com Content Network
Figure 2: Weight (W), the frictional force (F r), and the normal force (F n) acting on a block.Weight is the product of mass (m) and the acceleration of gravity (g).In the case of an object resting upon a flat table (unlike on an incline as in Figures 1 and 2), the normal force on the object is equal but in opposite direction to the gravitational force applied on the object (or the weight of ...
In the first case the force is continuously applied to the car by a person, while in the second case the force is delivered in a short impulse. Contact forces are often decomposed into orthogonal components, one perpendicular to the surface(s) in contact called the normal force, and one parallel to the surface(s) in contact, called the friction ...
An alternative definition of the plasticity index has been given by Mikic. [32] Yield occurs when the pressure is greater than the uniaxial yield stress. Since the yield stress is proportional to the indentation hardness σ 0 {\displaystyle \sigma _{0}} , Mikic defined the plasticity index for elastic-plastic contact to be
In mechanics, strain is defined as relative deformation, compared to a reference position configuration. Different equivalent choices may be made for the expression of a strain field depending on whether it is defined with respect to the initial or the final configuration of the body and on whether the metric tensor or its dual is considered.
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 definition of strain rate was first introduced in 1867 by American metallurgist Jade LeCocq, who defined it as "the rate at which strain occurs. It is the time rate of change of strain." In physics the strain rate is generally defined as the derivative of the strain with respect to time. Its precise definition depends on how strain is measured.
The index n usually lies between the values of 2, for fully strain hardened materials, and 2.5, for fully annealed materials. It is roughly related to the strain hardening coefficient in the equation for the true stress-true strain curve by adding 2. [1] Note, however, that below approximately d = 0.5 mm (0.020 in) the value of n can surpass 3.
Probability density of stress S (red, top) and resistance R (blue, top), and of equality (m = R - S = 0, black, bottom). Distribution of stress S and strength R: all the (R, S) situations have a probability density (grey level surface).