A metal structure is a structure made of metal. Distinguish between construction, industrial, agricultural metal structures, heavy and light, internal and external, barrier and protective. The design and calculation of such is an important point on which their strength and reliability depend.
It is necessary
- - all possible dimensions of the metal structure indicated in the project or on the drawing of the proposed construction;
- - sections;
- - pairing;
- - loads;
- - special software.
For the design of steel structures, data from certain load combinations are used. The latter can be dynamic or static.
Static loads in a certain position act constantly and are directed vertically, therefore they are also called gravitational.
Dynamic loads can arise, disappear, change the location and strength of the application. These include wind, precipitation, temperature fluctuations.
To calculate the strength of a metal structure, take the value of the maximum force acting on the structure, which is determined in accordance with the technical specifications, and multiply by the safety factor. If there are no vibration loads, then this is sufficient for the calculation.
Calculate using the limit state method. The first limiting state is the bearing capacity of the metal structure. Upon reaching this state, the structure suffers changes in its shape or loses its ability to resist external influences.
The condition for the first limiting state looks like this: N≤Ф, where N is the force in the structural element, and Ф is the limiting force that determines the resistance of the element. In the second limiting state, unacceptable vibrations or deformations appear. Its condition: δ ≤ δпр, where δ is the deformation of the structure as a result of external influences, and δпр is the ultimate deformation.
The third limiting state is characterized by the appearance of cracks, in which further operation of the structure is impossible. For this limiting state, use the formula: e ≤ epr, where e is the crack opening.
Use programs for the calculation of steel structures, such as "Frame" (from the SCAD collection), MSC.Software, Nastran, Lira, ANSYS and other software for engineering calculations.