Vibration Test Of Elastic Bundle Based On High-speed Photography Imaging Technology

The vibration characteristics of elastic bundle which as heat transfer components of heat exchangers had an important influence on heat transfer performance and service life of heat exchangers. Therefore, the in-depth study on vibration characteristics of elastic bundle was very necessary. The theory research was much more matured, and scholars had focused on experimental study about natural vibration characteristics of non-work elastic bundle. In order to study on the vibration test of working elastic bundle, a non-contact measurement method which based on high-speed photography imaging technology was adopted, and studied by combining theory research and experiment proving. The contents of research were as follows:Considering of the research and on learning about the common steps of image acquisition and processing, the whole functions of design image acquisition and processing software which was needed by the vibration measurement method based on high-speed camera were designed first. The whole software can be divided into six function modules. They were image acquisition, image opening and displaying, image preprocessing, target testing, and target tracking. Then the software was completed by C++ based on Microsoft Visual Studio.NET 2003, MFC, NI-IMAQ and OpenCV. The software was common useful and could be used for other research about dynamic image acquisition and processing.For verifying the feasibility of vibration test method based on high-speed photography imaging technology, the test method was designed, and the displacement sensor and high-speed camera were tested, and in the same experimental conditions, a cantilever beam vibrated under simple harmonic excitation, the vibration of the beam was measured with the contacting measurement method based on displacement sensor and non-contacting measurement methods based on high-speed photography imaging technology at the same time. Through data procession and error analysis, the results dedicated that the vibration test method based on high-speed photography imaging technology was feasible and its measurement precision could be further enhanced.Vibration test method based on high-speed photography imaging technology was applied on research about vibration test of elastic bundle. First, high-speed camera was tested, then the elastic bundle vibrated under pulse harmonic excitation and the vibration was measured by non-contacting measurement method which was based on high-speed photography imaging technology, last the feasibility of vibration test method based on high-speed photography imaging technology being used for working elastic bundle was analyzed. The results dedicated that the vibration test method based on high-speed photography imaging technology was useful for vibration measurement of working elastic bundle and after pulse harmonic excitation the vertical vibration frequency of elastic bundle was fixed and its vibration amplitude decayed over times.