What is Hertzian contact theory?
Table of Contents
What is Hertzian contact theory?
Hertz theory assumes that surfaces are continuous and nonconforming, strains are small, each solid can be considered as an elastic half-space, and surfaces are frictionless. Under these assumptions, only normal pressure acts between two bodies due to Hertz contact producing normal displacements of the surfaces.
What is Hertzian contact tribology?
In mechanical engineering and tribology, Hertzian contact stress is a description of the stress within mating parts.
What is Hertz equation?
This is the Hertz equation and generally Ra may be written as a mutual radius of curvature where. (35) Ra1 and Ra2 are the radii of curvature in a particular plane. If the solid bodies are molecularly smooth or highly deformable (a soft rubber), equation (34) may be used to calculate A directly.
What are contact stresses?
Contact stress is damage to the tissue of the body caused by contact between soft tissue and a hard object. Contact stress may be internal or external.
What is maximum contact pressure?
The maximum contact pressure which is carried purely elastically in the steady-state is known as the ‘shakedown limit’ and is the rational design criterion for tribological contacts such as ball bearings and railway rails and wheels.
How do you calculate contact pressure?
Contact pressure = Applied Load/ Area of contact.
What is the formula of contact pressure?
What is contact radius?
The contact radius between two objects depend on their material properties (e.g. elasticity) and on their geometry. If you press a rigid sphere into a fluid then after a while the wet area has radius a = sqrt(2Rh-h^2).
What is the contact pressure?
The contact pressure is the ratio of the normal load to the true contact area, which is the sum of the front and rear areas. It may be called the scratch hardness only in the case of plastic contact.
What is difference between TYRE pressure and contact pressure?
(iii) Tyre pressure is effective in surface layer while contact pressure is effecting throughout the thickness of the pavement i.e. thickness of pavement is affected by contact pressure, not by tyre pressure but contact pressure depends on tyre pressure.
How is tyre contact area calculated?
For small tyres with little distortion, O’Sullivan used McKyes’ simplified model, in the form A = a × W × D (A, W, D for contact area, width of the wheel and outer diameter of the wheel, respectively).
How big is a tire contact patch?
A compact car tire’s contact patch size is about 25 square inches, a bit bigger than the size of a 4” x 6” printed picture. The shape of a tire’s contact patch is also dependent on the tire’s profile (aspect ratio).
What is TYRE imprint area?
It is commonly used in the discussion of pneumatic (i.e. pressurized) tires, where the term is used strictly to describe the portion of the tire’s tread that touches the road surface. The term “footprint” is used almost synonymously.
How do you calculate contact patches?
The size of the contact patch is roughly equal to the weight of the car divided by the compressed air pressure inside the tires. This is not a perfect equation, however, since the size of the contact patch is also influenced by the stiffness of the sidewalls and other physical properties of the tire.
How do you calculate tire contact area?
The size of the contact patch is roughly equal to the weight of the car divided by the compressed air pressure inside the tires.
What is tyre pressure and contact pressure?
Contact pressure = Load on wheel/Contact area. Tyre pressure = Pressure inside the tyre.
How is TYRE contact area calculated?
What affects the size of the contact patch?
A tire contact patch’s final dimensions depend on the tire size and inflation pressure being used, as well as how much load is being carried. A compact car tire’s contact patch size is about 25 square inches, a bit bigger than the size of a 4” x 6” printed picture.
Is a wider tire better for cornering?
2. Improved Cornering. The same aspect of having a wider contact area with the road with the above, wider tires offer better cornering and road handling. It is also because wider tires have a better thread and stiffer sidewalls that they have less vehicle roll in corners.
