Area load
A surface load f , sometimes also surface pressure , is a load caused by forces that are not concentrated (punctiform) or distributed over a distance , but that are continuously distributed over an area .
The term can be found in technical mechanics , especially statics .
In vehicle technology and road construction , the term 'surface pressure' was sometimes used until the middle of the 20th century, with the same physical meaning, but applied, for example, to the contact surface of a tire with the road.
A surface load results from a traction vector (e.g. surface pressure, tension, shear stress) (e.g. water level in a canal bridge or a volume force times the thickness).
A surface load is a stress that has the dimension force per surface , e.g. B .:
with the force . The ratio is formulated differentially , since the surface load is generally not constant over the surface .
Special examples are the following effects in structural engineering :
- Payloads , for example the traffic load of a bridge , which is distributed over both the length and the width.
- Dead weight times the thickness of, for example, bridge girders and their traffic route superstructures ( coverings , bulk goods , rails )
- Wind loads on walls and roofs,
- Snow loads on roofs .
Typical area load assumptions can be found in the relevant standards or in construction tables (e.g. from Schneider construction tables , Werner Verlag).