Shear chain design of Cell type rubber fender

Shear chain design of Cell type rubber fender

When the ship berths at the wharf, most of the ships will first collide with the wharf at 1/3 and 1/4 lengths away from the bow or stern. As anti-impact equipment of wharf, rubber fender must bear not only the normal impact force perpendicular to wharf quay wall, but also the tangential force parallel to wharf quay wall. Under normal operating conditions, the cell type rubber fender can withstand the tangential force of the ship. However, when the shear deformation of the rubber fender barrel exceeds the specified requirements, the shear chain must prevent the shear deformation of the rubber fender barrel. Therefore, shear chain plays an important role in ensuring the normal operation and reasonable performance of drum fender.

The design method of drum rubber fender shear chain is introduced below.

1. Layout of shear chains

The shear chain is generally arranged on both sides of the rubber fender, with one end fixed on the anti-impact plate and the other end fixed on the quay wall (Figure I). Shear chain generally adopts ordinary chain, its specification and quantity are determined by the specification of rubber fender, the arrangement of rubber fender and the size of anti-impact plate.

Figure I

2. The length of shear chains

The design principle of shear chain is to ensure that the shear deformation of cell rubber fender does not exceed the specified requirements under the most unfavorable berthing conditions. It is assumed that the design deformation rate of drum rubber fender is 50% and the allowable shear deformation is C. As shown in Figure 2

C: Allowable shear deformation of a drum type rubber fender;

D:Horizontal projection of shear chain on quayside wall of rubber fender under unloading condition;

H: drum rubber fender height.

Shear chain of cell type rubber fender shall be arranged horizontally on both sides of rubber fender

The length l is calculated according to the formula. One end is fixed on the anti-impact plate, and the other end is fixed on the embedded U-ring