Research On Monitoring Stress And Vibration Online For Shipbuilding Crane

The stringent requirements of working reliability and safety for lifting equipment are put forward by modern port. In order to ensure the safe operation of mechanic equipment and improve the reliability and safe operation rate, it is very necessary to do the modern fault diagnosis and state inspection. For "The Assessment For The Safe Operation Of Ship Built Hoisting Machinery"(project number:2011QK236), science and technology planning project of General Administration of Quality Supervision, Inspection and Quarantine, the stress of the shipbuilding crane and vibration on-line monitored is investigated. According to the actual demand of online monitoring of shipbuilding crane, on-line monitoring method on the metal structure of the crane and the selection method of test points have been studied. And a kind of online monitoring system applied to shipbuilding crane based on the technology of wireless LAN transmission has been designed. On the question of the stress monitoring and the selection of vibration measuring points, we have put forward a test point’s relevant theory of crane’s metal structure and we also have done some relevant case analysis.Firstly, stress monitoring system, vibration velocity monitored system and Wi-Fi network transmission system have been designed based on modular design idea. In order to improve the precision and stability of the crane on-line monitoring system, the method that combination of strain signal preamplifier and data lineate transmission is adopted.Secondly, in view of the problem that it is difficult to online monitoring the stress and vibration of portal crane boom system, basing on relevance theory of the measured point, other points are applied to instead the measured points. The boom system is simplified into four bar linkages and the equivalent stress distribution is calculated. And according to the calculated results correlation, boom’s measured points’ relevance character on boom is analyzed.Finally, according to the proposal of online monitoring, the stress and vibration online experiments for S4588type crane are conducted. The stability of the stress results has been analyzed and it verified the measured points’ relevance results of the S4588type crane.According to the experimental data, it is did the fatigue residual life calculation of the main metal components of the crane.