Farm Equipment and Hydraulic Equipment
Berkeley Engineering and Research is centrally located in the San Francisco Bay Area and adjacent to California's agricultural central valley. Our engineers, metallurgist and agricultural economist have worked on a large number of litigation cases related to construction equipment, farm equipment and farm evaluation.
Tractor Bucket drops unexpectedly
Farm vehicles and equipment, combines, harvesters, lifts and tractors are engineered to safely accomplish amazing tasks. Unfortunately operation of these machines happens in real world environments with weather, slippery surfaces, and uneven grading.
The most common farm equipment failures are rollovers and collisions invovling human error. However, in a recent case, BEAR engineers identified the failure of a hydraulic hose fitting that resulted in the drop of a tractor backhoe bucket crushing the tractor's owner.
In the picture above, an electronic load cell was used to determine the stress exerted on the fitting if pinched between the lift cylinder and a branch or other large piece of debris.
Testing exemplar brazed fittings, top row – right, shows separation at the brazed joint if the fitting is pushed against the cylinder. Testing a forged fitting which actually costs less, lower row-right, shows that the fitting will bend and not fracture as the brazed fitting.
BEAR engineers determined that brazed fittings are unsuitable for critical locations and cost more than forged fittings.
To show exactly why the subject brazed fitting fractured, a computer based finite element analysis (FEA) was performed as shown in the graphics to the left. The lighter color indicates higher stress, and shows the stress and deformation concentrates at the brazing.
Our team of mechanical and metallurgical engineers, using BEAR's systematic, scientific approach to failure analysis was able to convincingly show this was a design defect. The case easily settled without trial.