How to choose the heavy duty rack column! Heavy shelf is an important carrier to improve the efficiency of warehouse use, and to enhance the efficiency of storage and retrieval, and it has been widely used in all walks of life. Removable shelves and modular shelves, according to the pitch height can be adjusted, so that the shelf layer spacing can be placed with the goods of any size adjustment, randomness and flexibility of increasing inventory, also has the component of small size, warehouse utilization rate is high, easy to manufacture, assemble and install interchangeable advantages such as short cycle, as one of the most widely used in the shelf.
The upright post is the ultimate force bearing component of the detachable shelf. The design is the key of the whole shelf system, which is directly related to the safety of the structure and the economy of the use. Assembled rack is mainly composed of a column piece, beams and other basic pieces and beads, angle, spacer, spacer, laminate (plate or board) and other selected parts. Column is the main component of the shelf life of the load, bearing the maximum amount of up to 21 tons. With the increase of the height of the shelf, layers increased, column loading, and most of the cold-formed thin-walled steel punching, the residual stress processing itself, the actual stress situation is more complicated, so the column design become the key of the shelf system, directly related to the safety and economic structure.
Section shape of column
From the cross section, section shape of the column there are many, but the current market distribution, basically mainstream profile or steady basic map of the shelves, some of which section structure is relatively simple, mainly for the light shelf; multilateral roll structure is relatively complex, the processing technology is relatively complicated, mainly used in heavy shelves. The other shape derived from the basic type is mainly to increase the bending over the long side of the length, in order to improve the stiffness and stability of the column. In the specific design, in addition to considering the strength, stiffness and stability of the structure, the general effect of pre processing conditions should also be considered, forming concrete to pass the blank on the quality of products, such as pre punching and bending deformation in cold roll line of product quality, such as cold deformation in the process of pre punching. Under the premise of ensuring the requirement of size tolerance and ensuring the hole spacing, the design of section shape should take into account the requirements of different thickness, and the fixed bending radius.
Two, cross beam hole
The front face of the vertical column is uniformly distributed with a lot of long holes (a hook hole) and a circular hole, which is used for hanging the hook of the cross beam, and the safety pin is installed.
Pass by, usually inverted eight diamond or obtrapezoid, the long hole column with a small angle with the vertical direction, hanging on after the goods under the action of gravity automatic locking, and the surface between the hook and the vertical long hole contact, good stress state, to ensure more stable security. However, the opening of the hook hole has a great influence on the bearing capacity of the column, the bearing capacity of the open hole is 70%~95%, and the influence of the column of the small size is bigger. Therefore, under the condition of satisfying the bearing capacity of the beam, the size and the number of the hook holes should be reduced as little as possible so as to improve the overall carrying capacity of the shelf.
Three, design check
Because of the post is the main bearing part of the shelf, the shape structure is relatively complex, and most of the cold-formed steel (itself some residual processing stress loading), the situation is more complex, especially the top shelf, multiple layers, large load, so that the design of redundant column fan, check the value of complex. Reasonable or not directly related to the safety of the structure.
Four, strength and stability check
The calculated strength: 1 shelves in calculating the strength of the column, according to the different load conditions, required respectively according to axial compression and bending are calculated by checking "cold-formed steel structure technical specifications" (GB50018 - 2002) the relevant formula.
2: Although the shelf stability calculation of a thin steel plate column is formed by cold rolling, column section after repeated bending, local buckling phenomenon does not appear, but with the application of shelf pillar section constantly enrich the form and high strength steel, the compression column toward the light, thin direction, easy to cause the instability of the column therefore, the stability of compressed column component becomes more and more important.
3 Analysis and practice have confirmed that the column with the material mechanical properties, mold design, manufacture precision is the column bearing capacity and stability of the main factors, changes in the size of all pass has a direct impact on the stability of the material section of local thinning has little effect on the stability of the.