船舶板架结构变形场测量技术研究

Deformation field measuring technique of ship grillage structure

船舶结构强度试验过程中,传统的离散点变形测量技术难以获得结构的全场变形数据,因而无法有效揭示结构的渐进破坏过程。本文基于数字图像相关和三维激光扫描原理,提出适用于船舶板架结构变形测量的位移形函数与子区相关性准则,发展定量可控的数字散斑场制作方法,形成船舶板架结构几何形貌测量方法,建立船舶板架结构变形场测量技术;在此基础上,开展船舶板架结构模型变形场演化过程测量试验,获得模型在纵向压缩载荷所用下的结构变形场,尤其是模型结构临界状态前后的失效演化行为,揭示船舶板架结构变形场的时空演化规律,可为实船结构的失效模式识别提供基础测量技术手段。

In the course of ship structural strength experiment,it is difficult to obtain the full field deformation data of a structure by the traditional discrete point deformation measuring technique.Therefore,the progressive destruction process of a structure cannot be effectively revealed on the base of the method.In this paper,the deformation field measuring technique of a ship grillage structure was established based on the principle of digital image correlation and 3D laser scanning.The displacement shape function and correlation criterion of subset were proposed for deformation measurement of the ship grillage structure.Moreover,a digital speckle making tool was developed in order to obtain a quantitative and controllable digital speckle field.Based on a portable 3D laser scanning system,a method for measuring the geometry of ship grillage structure was presented.An experiment was carried out to verify the deformation field measuring technique of ship grillage structure.The structural deformation field of the model under longitudinal compression load was obtained by the experiment,and the failure evolution behavior was found before and after the critical state of the model structure.Through the above experiment,the space-time evolution law of deformation field for the ship grillage structure was revealed.A basic measuring technique for failure mode recognition of real ship structures was provided in this paper.