Thin-walled Steel Geometric Imperfection Measurement System Development And Experiment Research

With the development of science and technology, cold-formed thin-wall steel has got highly attention of all walks of life as a new type of materials. It’s energy-saving and environmental, and its performance analysis has been one of the most important testing programs. Geometrical imperfection has great influence on the performance of the cold-formed thin-walled steel. Therefore, it has important significance to researching on the measurement of cold-formed thin-wall steel’s geometrical imperfection.Based on the buckling testing research of cold-formed thin-wall steel in laboratory, a measurement system is designed to measure the geometrical imperfection of cold-formed thin-wall steel. In this measurement system, a laser displacement sensor is used to measure the radial coordinate values,and a PLC is used to control two stepper motors to get to the right measuring position. The three-dimensional geometric shape of the test piece is formed by measuring lots of measured points.According to the design parameters and theory of the measurement system, the mechanical structure and control system are designed and described in detail.The three-dimensional model of the measurement system is established in SolidWorks. Measuring path is reasonable planned and main factors which lead to measuring error are analyzed.Then calibration experiment is conducted on the measurement system.The experimental results show that the repeatability error of the measurement system is less than0.4%and the measurement error is less than0.2mm. The results conform to the design index, verify the rationality of the measurement system.