Hydraulic Hose Modal Behavior to Investigate Structure-Borne Energy Transfer

High pressure hydraulic fluid lines tend to cause significant structure borne energy transfer at clipping points that can result in vibrations and noise. The hydraulic noise and vibration can be an annoyance or serious hearing risk for workers and may contribute to fatigue failure of components. Optimization of hose clamping points is suggested as a passive method to reduce energy transfer from the hose to supporting structural components. By examining the fluid operating deflection shape, regions of high and low structure-borne noise can be predicted at dominant pump orders. A test bench has been developed to compare these assumptions with experimental data. An energy balance method was developed to predict the fluid-borne noise (FBN) energy at hose clipping points. Measurement of the energy at a clipping point presented a challenge because structure-borne noise and fluid-borne noise could not be measured simultaneously. Hose pressure ripple frequency response functions (FRFs) were generated and used to predict the local pressure ripple at a location where it is desired to measure structure borne noise and fluid borne noise. The results of the generated pressure ripple FRFs are discussed and compared with measured pressure FRFs. Preliminary results from the energy balance method are discussed as well as possible sources of error.