Following several recent incidents involving dislodged in-pavement airport runway light fixtures, a comprehensive engineering assessment was performed in order to mitigate future light fixture issues. The engineering assessment consisted of an immediate root cause evaluation, followed by phases that addressed both short-term and long-term corrective actions.
Root cause analysis of the incident light fixtures revealed the bolts affixing the fixtures to the light bases fractured due to fatigue under cyclic loading. To determine the contributing factors to the fatigue failures (e.g., aircraft loading, installation requirements, maintenance practices) further evaluation included a sampling program to ascertain the current state of in-service light fixtures, finite element analysis of light fixture loading scenarios, light fixture bolt torque testing, and data acquisition of instrumented runway light fixture assemblies.
The primary findings from the ongoing assessment indicate aircraft loading, light fixture installation, and maintenance all play a role in the mechanical performance of the fixture assemblies. Current light fixture bolt torqueing (pre-loading) practices are not sufficient to withstand larger, modern aircraft loading, and bolt pre-load levels should be increased. In addition, design and use of the light fixtures should take into account the finding that the fixture assemblies and pavement act as a system when reacting to aircraft loading, such that light fixtures sustain cyclic loading even without direct aircraft contact. LPI’s Julia Grogan presented these findings at the 2015 Technology Meeting of the Illuminating Engineering Society Aviation Lighting Committee.
LPI recently used a motion amplification camera (MAC) system on a custom platform to measure vibrations on the main steam lines at Grand Gulf Nuclear Station.
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Come visit LPI at the CLM Midwest Conference in Chicago! LPI, Inc. will have a table top exhibit at the CLM Midwest Conference in Chicago, IL June 14th-15th 2018. We invite you to stop by our table top booth to talk with Dr. Zuhair Ibrahim to learn ab
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LPI partners with Argonne to support nuclear power plant operations
At LPI, we use a variety of such programs to tackle a diverse group of client projects that may involve failure investigations, anomalous operational conditions, or new design.
LPI's reputation for providing reliable fitness-for-service skills to clients is well known. Perhaps less well known, however, but equally a core service it offers to clients, is LPI's ability to enter a product's design cycle early on and provide expert
Integrated Life Cycle Management model developed by LPI, Inc.
LPI was requested to perform an engineering evaluation of a fractured expander wheel to determine the root cause of failure and corrective actions required to prevent future failures.
LPI Principal Joseph Crosson, P.E. was included in a profile of the original classes of Certified Welding Inspectors (CWI) featured in the February 2016 issue of Inspection Trends, a magazine published by the American Welding Society (AWS).
Sri K. Sam Sinha, P.E., Managing Director of LPI Inc., has been appointed as a member of ASME Board on Pressure Technology Codes and Standards for a term effective January 2016 through June of 2020.
