Problem

In a legal case involving a broken saddle adapter for a lifting jack, Kent Engineering (KE) performed an independent analysis of the failed part giving an expert opinion for the reason the adapter failed. As a result of the data and opinions gathered from Kent Engineering’s analysis, a settlement was reached.

Scope | Methodology

Many tools were used during this independent analysis. The fractured part was observed with optical microscopy as well as under a Scanning Electron Microscope (SEM). KE was able to identify fracture morphology from the pictures gathered that gave information such as crack direction and mode. The SEM also allowed for the relative composition of the material to be determined using X-ray Energy Dispersive Spectrometry (EDS). This in combination with microhardness measurements helped the engineers determine the strength of the material that failed. Lastly, Finite Element Analysis (FEA) was performed to assess the design of the adapter and pinpoint places of extreme stress during loading. All these pieces were analyzed by the engineers at KE and the puzzle was solved leading to KE’s expert opinion on the cause of failure.

Root Cause | Solution

Kent Engineering was able to determine that the saddle adapter for the jack in question was not designed properly, with unrealistic loading expectations designed into it. Because of the design, there was a specific point on the adapter that created a stress concentration. In addition, to lessen the stress from becoming too great the adapter must be fully inserted into the jack which was difficult due to tight tolerances between the mating surfaces. Those tight tolerances which when worn and made loose expounded upon the stress delivered to an already susceptible stress concentration further promoting a failure of the adapter while loaded.

Leading Experts in Forensic and Litigation Support

At Kent Engineering, we provide forensic and expert witness support across a variety of industries, including construction, multifamily, manufacturing, transportation, plumbing, heavy equipment and machinery, food processing, and maritime. Our staff of engineers and architects lend their range of specialties and deep expertise to each industry, inspecting and identifying failures in order to help represent our clients well.

Find out how Kent Engineering the right partner for your engineering, analysis, and inspection needs. Feel free to get in touch with us; we are here for you!