深海重力活塞取样器冲击取样系统动力学特性分析

发布时间：2018-05-16 13:22

本文选题：重力活塞取样器 + 海底沉积物　；参考：《湖南科技大学》2015年硕士论文

【摘要】：深海重力活塞取样器是当前用于采取海底长芯柱状软泥沉积物的基本设备之一。本文以30米重力活塞取样器为研究对象,综合运用波动力学、岩土力学、数值模拟以及有限元分析等理论与方法,深入分析重力活塞取样器冲击取样系统的动力学特性以及取样性能,展开对重力活塞取样器冲击系统波动力学建模、冲击参数对冲击取样系统性能的影响分析以及重力活塞取样器冲击取样有限元分析的研究。主要研究内容如下:(1)首先介绍本文工作的背景,明确进行重力活塞取样器冲击取样系统动力学特性分析的重要意义,对国内外重力活塞取样器发展现状以及冲击系统动力学相关研究工作进行归纳与总结,给出本文的主要研究内容与总体思路。(2)深海重力活塞取样器冲击取样系统波动力学建模及数值计算。深入分析重力活塞取样器冲击取样工作原理及结构特点,考虑深海沉积物力学特性,应用波动力学理论,构建重力活塞取样器冲击取样系统波动力学模型。并依据此模型研究重力活塞取样器冲击系统冲击取样过程的数值计算方法,通过Matlab编制模拟程序,进行重力活塞取样器冲击取样数值模拟与计算。(3)深海重力活塞取样器冲击取样性能分析。以冲击取样效率与贯入深度为性能指标,通过数值模拟,分析了取样器配重、冲击高度、取样管直径以及沉积物特性等因素对重力活塞取样器冲击取样性能的影响,得出冲击取样参数对重力活塞取样器贯入深度与冲击取样效率的影响规律,同时对取样器冲击部件内部应力进行分析,给出冲击参数的选取范围。(4)深海重力活塞取样器冲击取样系统结构有限元分析。基于ANSYS/LS-DYNA软件,建立深海重力活塞取样器冲击取样有限元模型,仿真分析取样器自由下落冲击取样过程中取样管冲击海底沉积物的动态响应,得出海底沉积物坡度、取样器攻角、取样管壁厚以及沉积物类型对深海重力活塞取样器取样管冲击应力的影响规律,进而为重力活塞取样器的结构设计、实际应用及性能评估提供理论指导。
[Abstract]:Deep-sea gravity piston sampler is one of the basic equipments for taking long core silt sediment. In this paper, a 30m gravity piston sampler is studied, and the theories and methods of wave mechanics, geotechnical mechanics, numerical simulation and finite element analysis are used synthetically. The dynamic characteristics and sampling performance of impact sampling system of gravity piston sampler are analyzed in depth, and the wave mechanics model of impact system of gravity piston sampler is established. The effect of impact parameters on the performance of impact sampling system and the finite element analysis of impact sampling for gravity piston sampler are studied. The main research contents are as follows: (1) first of all, the background of this work is introduced, and the significance of analyzing the dynamic characteristics of the impact sampling system of the gravity piston sampler is made clear. The development status of gravity piston sampler at home and abroad and the related research work of impact system dynamics are summarized and summarized. The main research contents and general idea of this paper are given. (2) Wave mechanics modeling and numerical calculation of impact sampling system for deep-sea gravity piston sampler. The working principle and structural characteristics of impact sampling of gravity piston sampler are analyzed in depth. Considering the mechanical properties of deep-sea sediment, the wave mechanics model of impact sampling system of gravity piston sampler is established by applying wave mechanics theory. According to this model, the numerical calculation method of impact sampling process of gravity piston sampler impact system is studied, and the simulation program is compiled by Matlab. Numerical simulation and calculation of impact sampling for gravity piston sampler. Taking the impact sampling efficiency and penetration depth as the performance indexes, the effects of the weight of the sampler, the impact height, the diameter of the sampling tube and the sediment characteristics on the impact sampling performance of the gravity piston sampler are analyzed by numerical simulation. The influence of impact sampling parameters on penetration depth and impact sampling efficiency of gravity piston sampler is obtained. The structural finite element analysis of impact sampling system for deep-sea gravity piston sampler is given. Based on ANSYS/LS-DYNA software, the finite element model of impingement sampling for deep-sea gravity piston sampler is established. The dynamic response of the sampling tube to the seabed sediment during the sampling process of free-fall impact is analyzed, and the slope of the sediment and the angle of attack of the sampler are obtained. The influence of the wall thickness and sediment type of the sampling tube on the impact stress of the sampling tube of the deep sea gravity piston sampler provides theoretical guidance for the structural design, practical application and performance evaluation of the gravity piston sampler.
【学位授予单位】：湖南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P715.1

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