薄壁件装夹贴合状态在机超声检测技术

发布时间：2018-04-19 03:05

本文选题：贴合状态 + 超声　；参考：《大连理工大学》2014年硕士论文

【摘要】：大型薄壁零件具有刚度低、壁薄、容易变形、加工精度要求高等特点,因此对装夹工艺有着严格的要求。目前采用的一种内撑式装夹方法,是利用高压力把薄壁件与内撑式夹具压紧贴合在一起。两者的贴合状态对提高薄壁件的加工精度具有十分重要的作用,理想状态是薄壁零件与内撑式夹具能够完全贴合,没有缝隙。如果贴合状态不好,则需要对薄壁件进行重新装夹。目前还没有一种对薄壁件与内撑式夹具贴合状态判定精度高、自动化程度好的检测方法。本课题研究方向为构建应用于分析薄壁件与内撑式夹具贴合状态的在机超声检测系统。本文对粗糙表面接触特性进行了分析,结合流体力学、水声学、超声检测方法等相关知识,对以下问题进行了深入研究： (1)通过对薄壁件装夹中的粗糙表面接触特性进行研究,确定了利用超声测量原理对薄壁零件与内撑式夹具的贴合状态进行检测的方案。 (2)研究了流体特性对超声波信号散射衰减的影响以及液浸超声检测法对耦合液状态的要求。 (3)利用计算流体动力学软件FLUENT6.3对喷水器内部的水层进行建模。通过仿真分析确定了喷水器的结构形式和尺寸参数。 (4)设计了基于喷流液浸法的贴合状态在机超声检测系统。对“钢珠——平板”试验件的贴合状态进行了在机测量,获得了试验件粗糙面接触特性的相关数据,验证了该检测方案的可行性。
[Abstract]:A large thin-walled part with low stiffness, thin wall, easy deformation, demanding high precision, so it has strict requirements on the clamping process. Currently used a prop clamping method, is to use the high pressure to the thin-walled member and the inner supporting fixture clamping fit together. The binding status two has an important role in improving the machining accuracy of the thin-walled parts, the ideal state is a thin wall part and the inner supporting fixture can completely fit, there is no gap. If the fitting condition is not good, then the need for thin-walled parts are clamping again. There is no kind of thin wall member and the inner supporting fixture fitting state determination high precision detection method of automation. The research direction for the construction of application to the analysis of thin-walled bracing fixture in the machine fitting state and ultrasonic detection system. Based on the analysis of rough surface contact characteristics, node merging The following problems are studied in detail: body mechanics, hydroacoustics, ultrasonic testing methods and other related knowledge.
(1) through studying the contact characteristics of the rough surface in the clamping of thin-walled parts, the scheme of measuring the bonding state between the thin-walled parts and the inner bracing fixture is determined by the ultrasonic measuring principle.
(2) the effect of fluid characteristics on the attenuation of ultrasonic signal scattering and the requirements of liquid immersion ultrasonic testing on the state of coupling liquid are studied.
(3) use the computational fluid dynamics software FLUENT6.3 to model the water layer inside the sprinkler. Through simulation analysis, the structure and size parameters of the sprinkler are determined.
(4) a computerized ultrasonic testing system based on jets is designed. The bonding state of the steel bead plate test is measured in machine. The relevant data of the rough surface contact characteristics of the test piece are obtained, and the feasibility of the test scheme is verified.

【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB553

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