A Comparative Study of Strain Gauge and Load Cell-Based RLD Methods for Assessing Structural Durability Loads in Engine Mounts

<div class="section abstract"><div class="htmlview paragraph">In the ongoing Road Load Data Acquisition (RLDA) for engine mounts, a load cell arrangement is being utilized, where the load cell must be placed between the mount arm and an engine mount bracket or an additional tower bracket. This configuration required the design of a custom mount arm with a crank in the Z direction, secured with a single bolt to accommodate the load cell. However, this method has revealed significant load coupling in the X and Z directions, resulting in incorrect load prediction for engine mount testing. This happens due to the architectural packaging of the engine mount on the long member to meet NVH requirements.</div><div class="htmlview paragraph">To mitigate these issues, an alternative strain gauge-based RLDA approach was investigated. The optimal locations for strain gauge placement were determined using the inverse matrix method with the assistance of Computer-Aided Engineering (CAE) analysis. Strain gauges were then installed at these identified locations on the mount arm. The engine mount, now equipped with strain gauges, was tested in a real vehicle under standardized driving conditions and tracks. The strain data obtained was subsequently converted into load signals through the inverse method, demonstrating a substantial reduction in coupling effects compared to the load cell arrangement.</div><div class="htmlview paragraph">This method not only provided more accurate load data but also presented a reliable alternative for RLD collection in engine mounts. A detailed case study is included to illustrate the correlation and effectiveness of this newly proposed RLDA process.</div></div>