Fabrication Tolerance Study of Cold-formed Steel Members Based on Geometric Point Clouds of Laser Sensor

摘要

Cold-formed steel (CFS) industry grows fast in the last decade where more and more structures were constructed using CFSs as major load-bearing members. CFS is known for its light weight and high strength. As the material is minimized, the CFS members are inevitably sensitive to dimension variations so as to the cross-section properties, cross-section stability modes, and the resulting strength. The objective of this paper is to explore characteristics of dimension variations of typical cold-formed steel members, geometric point clouds of which were taken from high-throughput laser sensor platform. Variations of dimensions along the length of a specimen are displayed where closeness relationship between adjacent dimensions are observed. Thus, the correlations among dimensions of measured CFS members are extracted based on the reconstructed true geometries. Moreover, the comparisons between manual measurements and laser measurements have been made. The results may provide reference to manufacturing tolerance which were determined from manual measurements decades ago and may contribute to significant financial impact for the manufacturers. Simulations are applied to dimensions of models based on statistic parameters extracted from the measurement data of laser sensor. Various geometric properties are generated and fabrication factors are concluded corresponding to different properties. It is expected that the study may provide better understanding of dimensional tolerance and their impact on fabrication factors, thus the structural performance, which in turn may affect decisions of fabrication tolerance for cold-formed steel industry.