Sensor (monitoring points) Layout Method for Fatigue Design Load Extraction

摘要

Selecting an appropriate concept design in the early stage of the product development process is crucial for successful machine development. As one of the important design requirements, a structural design needs to validate the structural fatigue life against physical tests of actual field operations. Obviously, the quality of a concept design depends on how well the design loads represent the actual fatigue loads. Traditionally, the fatigue design loads for the concept design evaluations are generated by hand calculations based on past experience to capture envelopes of expected system responses. But such an approach often does not capture actual loading behaviors in the field. An alternative approach of leveraging observed data from physical tests is highly desired, and a new method of this approach is introduced here. In this study, our goal is to develop a new sensor layout methodology using fundamental fatigue load contents extracted from observed data. Most existing optimal sensor layout methods, especially from the structural health monitoring field, focus on maximizing the detection of dynamic response changes of a target structure for possible structural damage. However, in this paper, the proposed sensor layout method aims at finding fundamental load patterns to capture the structural damage characteristics. The data measured from the proposed sensor layout will have a greater chance of retaining and highlighting unique fatigue load patterns that can be useful in concept design exploration. The proposed framework integrates techniques from data analytics, such as pattern mining, with fatigue mechanics to amplify and track down fundamental damaging load patterns. Numerical demonstrations and case studies of the proposed method are presented with a common structural component, an Ⅰ-section cantilever beam, and an industrial large-scale structure, a front linkage of a hydraulic excavator.