Bending behaviour of double-acting hydraulic actuators

The buckling behaviour of hydraulic actuators is often established by using simple analytical models. However, existing research does not take into account rectilinear imperfections and friction effects at the restrained ends and in the area of the rod-cylinder connection (the port through which the rod enters the cylinder). Recent research has tried to establish the effects of actual geometrical imperfections and friction on plunger-rod actuators, thus enabling better use of these very common mechanical components. This paper analyses the bending behaviour of hydraulic piston-type actuators using analytical models, able to take into account friction, rectilinear imperfections and the actual geometric configuration of piston-type actuators. The reliability of these analytical models was confirmed by means of experimental tests carried out on full-scale equipment.