Levyliitokset

Levyliitokset refer to bolted connections where two or more structural elements, typically steel plates or beams, are joined together by bolts passing through holes in the overlapping members. These connections are fundamental in steel construction, bridges, and various mechanical assemblies. The design of a levyliitos involves selecting appropriate bolts, washers, and nuts, as well as determining the number, size, and arrangement of bolts to withstand the anticipated loads.

The strength of a levyliitos is derived from the combined resistance of the bolts to shear and tension, and the bearing strength of the connected plates. Shear failure occurs when the bolts are pulled apart across their cross-section, while tension failure happens when the bolts are stretched until they break. Bearing failure involves the deformation or tearing of the connected plates around the bolt holes. Engineers consider these failure modes when calculating the load-carrying capacity of the connection.

Different types of levyliitokset exist, categorized by the manner in which loads are transferred. Bearing-type connections rely on the shear strength of the bolts and the bearing strength of the connected elements. Friction-type connections, on the other hand, utilize the clamping force created by pre-tensioned bolts to generate friction between the faying surfaces, which then resists the applied shear forces. This type of connection is generally preferred for its higher strength and ductility.

The fabrication and erection of levyliitokset require precise hole drilling, proper bolt tightening, and the use of appropriate washers to ensure even load distribution and prevent damage to the bolt threads. Quality control measures, such as bolt tension testing, are often employed to verify the integrity of the connection.