一发三收式桩基声波透射检测技术及数值模拟分析

桩基声测管倾斜会使得桩身混凝土超声波波速计算结果出现误差,影响桩身质量检测结果,为此提出一种一发三收式声波透射检测技术。该技术通过固定各声波接收换能器的间距,根据几何关系,使用检测得到的超声波声时和接收换能器的间距,即可计算得到桩身混凝土超声波波速,使其不再依赖于超声波发射端和接收端的间距,也不再需要拟合声测管管身曲线。通过有限元软件模拟接收换能器间距和声测管倾斜程度对检测结果精度的影响,结果表明该技术可以良好地适应超声波接收换能器间距和声测管倾斜斜率的变化,稳定保持较高的波速计算精度,解决声测管倾斜、偏位时造成的声速计算误差。     

测试装置重量对身管直线度测量精度影响分析

随着复合材料的广泛应用,复合材料身管直线度测量成为亟待解决的工艺难题,传统用于钢管直线度测量的装置将会引起较大的复合材料身管直线度测量误差,为此,应用ABAQUS有限元分析软件对处于不同载荷、不同支撑条件下的复合材料身管变形进行分析,建立复合材料身管三维有限元模型,分析得到不等重的测试装置在身管不同支撑条件下引起的复合材料身管变形量大小,设计相应试验验证有限元分析结果的正确性。结果表明测试装置自重及身管不同支撑条件对复合材料身管直线度测量精度产生重要影响,因此可以通过改变身管的支撑条件来降低测试装置自重的影响。采用数据拟合得到身管变形量和测试装置重量之间的关系,为复合材料身管直线度检测系统设计提供理论依据。     

火炮身管超声导波频散特性及传感器配置

超声导波检测技术具有检测距离远、效率高的优点,适用于检测火炮身管等圆管类结构,具有突出的军事应用价值和前景。首先对圆管超声导波理论进行推导,并对身管损伤的几种常见类型进行分析研究。采用数值计算的方法绘制频散曲线,通过分析其频散特性对导波检测频率进行优选,初步得到了最佳的检测频率范围;其次着重对传感器种类选择、数量及分布方式与导波传播特性的关系进行研究。实验表明,导波检测的最佳频率范围为0～300 kHz,且导波弯曲模态一般不宜作为检测模态;传感器数量的增加不仅增强了激励信号的强度,还有效抑制了身管中导波的频散。     

基于L(0,2)模态的身管损伤无损检测方法研究

火炮特别是新型火炮在现代战争中发挥巨大作用,身管是火炮的重要组成部分,其缺陷检测至关重要。利用Comsol有限元仿真软件模拟导波模态并与理论计算结果进行对比,验证有限元仿真的正确性和可行性。在对比研究L模态导波和T模态导波的基础上,给出一种基于L(0,2)模态导波的身管缺陷无损检测方法,并利用有限元仿真软件对L(0,2)模态在存在内表面非对称缺陷的身管中的传播过程进行仿真。理论研究和仿真结果表明,该方法可以用来识别不同种导波模态并对缺陷进行检测,为今后身管缺陷检测奠定基础。     

基于横向光电效应的火炮身管直线度检测系统研究

为实现对火炮身管直线度的量化检测,设计一种测量方法采用横向光电效应、内膛定位使用双滑块式自定心机构、电气控制使用PLC、检测软件基于LabVIEW的火炮身管直线度检测系统。在检测软件中通过倾角传感器采集数据对位敏传感器(PSD)位置进行修正后,PSD与位移传感器输入计算机中的数据根据直线度计算理论计算得到身管直线度的实际变化情况,最后采用最小二乘法对其误差进行评定。系统集精密机械技术、传感器技术及光电检测技术为一体,其中PSD的重复检测精度达到5μm,检测元件在定心精度为±7.86μm的机械结构装载下实现火炮身管直线度的高精度检测,可对我军口径在122～155 mm范围内的约25种制式火炮身管进行检测。     

纤维增强复合材料身管阻尼特性分析

针对火炮发射时纤维增强复合材料身管的阻尼效应,根据粘弹性材料动态特性,给出了纤维增强复合材料能量耗散公式,采用基于有限元技术的模态应变能分析方法,对某口径复合材料身管进行了阻尼特性分析,获得了该复合材料身管在各阶固有频率下的应变能和阻尼损耗因子,为复合材料身管的动态特性分析提供了阻尼特性参数.     

浅谈声波透射法在解决灰岩地区基桩桩身完整性的重要性

灰岩地区地质情况极其复杂,七洞、岩溶、构造带发育,地下水丰富甚至有地下暗河通道等,会影响桩基础的施工质量。为准确检测桩基础的质量情况,减少质量安全隐患和经济损失,必须选择合理的桩基础质量检测方法。而声波透射法是灰岩地区桩身完整性检测最有效、最准确的检测方法,声测管的埋设保护决定了声波透射法能否正常进行。本文总结声测管可能会出现的一些问题,阐述了声测管在声波透射法桩身完整性检测中的重要性。     

超声波探伤在某型追击炮身管检测中的应用研究

本文主要介绍了超声波探伤的基本原理和检测方法,并对液浸法在某型迫击炮身管检测中的应用作了详细的研究和探索,通过比较,深入分析了该方法的检测特点.     

火炮身管性能状态的灰色聚类评估方法

身管是火炮武器的重要部分,其性能状态决定了火炮的使用寿命.身管从开始使用到报废是一个逐渐的过程,目前多以身管寿命作为评价身管性能状态的指标,很少有对身管性能状态的细化分级.而正确评估身管当前的性能状态,就显得极为重要,这将极大地提高火炮武器的使用效率.运用灰色系统理论,建立灰色聚类评估模型,通过分析火炮身管性能状态的各种评估指标,综合评价火炮身管的性能状态,对战时作战协调具有明显的指导意义.     

火炮身管直线度检测系统总体设计

针对传统火炮身管直线度检测存在的深膛受限、精度较差、自动化程度较低等不足,设计了一种基于光电位置传感器的适用于不同口径、不同长度身管的火炮身管直线度检测分析系统,由直线度检测硬件分系统与直线度数据分析处理软件分系统组成．重点分析了检测硬件分系统的工作原理及各组件功用与组成,包括机械部分、光学部分和电路部分．该检测系统能满足现代化作战条件下武器系统快速、便捷检测的要求,具有较强的实用意义．     

The Effects of Inspection Error on a Complete Inspection Plan

In a complete inspection plan, every incoming item is subject to variable inspection. If the inspection result indicates that an item fails to meet predetermined specification limits, the item is reworked so that its quality characteristic is exactly equal to the target value. The specification limits are determined by the tradeoff among the cost incurred by imperfect quality, cost of rework and cost of inspection. The economic and statistical effects of inspection error on the complete inspection plan are investigated. Two models with considerations of inspection error are developed under different rework schemes, then compared with the model without inspection error consideration.     

State of the art in sensor technologies for sewer inspection

This paper reviews the state of the art in sensors and automated inspection devices for enhanced sewer inspection. Efficiency, safety, environmental, and legislative concerns have made inspection and assessment of communal sewers a central issue to water and sewerage companies. Nowadays, the standard sewer inspection system is based on a wheeled platform on which a closed circuit television (CCTV) camera is mounted. One of the disadvantages of camera inspection systems is that they can only detect a small proportion of all possible damage in a sewer. The inspection outcome of such systems relies not only on the quality of the acquired images, but also on the off-line. recognition and classification conducted by human operators. In consequence, CCTV-based platforms are frequently not effective. Infrared, microwave, optical, and ultrasonic-based sensors have been proposed to complement the existing CCTV-based approach and to improve inspection results. New inspection devices employing multiple sensors and being capable of carrying out remote sewer inspection tasks are under research     

高频焊接钢管焊缝的超声波自动检测工艺

在高频焊接钢管焊缝自动超声波检测的实际工作中,精确的焊缝跟踪较难实现,易影响检测的可靠性.通过对超声波检测技术进行分析,利用6 dB声束全壁厚覆盖区进行检测,提出了一套超声波检测新工艺.实践证明:该工艺可以在焊缝跟踪不精确的情况下实现可靠的超声波检测,为高频焊接钢管焊缝自动超声波检测提供了一套有效的检测方法.     

Visual Inspection of Highway Bridges

The Federal Highway Administration recently conducted an investigation to assess the reliability of visual inspection of highway bridges as implemented by state departments of transportation. The study focused on routine and in-depth inspection, the two most prevalent forms of visual inspection of bridges. Because visual inspection is a highly subjective nondestructive evaluation technique, the results of these bridge inspections can be highly variable and are dependent on many factors. This study included the completion of 10 bridge inspection tasks by 49 practicing state bridge inspectors. With regard to routine inspections, this study showed that condition ratings are assigned with significant variability. Specifically, approximately 68% of condition ratings are within 1 rating point of the average. The results of the in-depth superstructure inspections indicated that these inspections are not likely to detect and identify the specific types of defects for which this inspection procedure is sometimes prescribed. Specifically, widespread defects such as those normally noted during a routine inspection are likely to be noted; however, local deficiencies, such as crack indications, are unlikely to be detected. The results of the deck delamination survey indicate that the accuracy of this type of inspection is relatively poor, with few inspection teams providing results that could be considered to accurately portray the condition of the deck.     

Propagation of elastic waves in honeycomb panels for application to rapid inspection techniques

This paper considers the properties of elastic waves guided by an aluminum plate bonded to a honeycomb core for application to rapid inspection of honeycomb panels. Current acoustic inspection techniques involve the transmission of a signal between a pair of small transducers located on opposite sides of the panel. Scanning the transducers in raster fashion results in a high resolution inspection of the panel, but is very time consuming. An alternative technique would simultaneously inspect all points along a line between two widely spaced transducers located on the same side of the panel. Scanning the pair once over the panel permits rapid inspection, although with decreased resolution. Studies presented here indicate that such a method of inspection is feasible and that the flexural mode is probably the most useful.     

Inspection resource assignment in a multistage manufacturing system with an inspection error model

Producing high-quality products at low cost is always one concern for a multi-stage manufacturing system. That is, production costs and inspection efficiency should receive equal importance. Inspection planning to allocate inspection stations should then be performed to manage limited inspection resources during process planning. Product quality and the possible costs can then be concurrently considered when evaluating a manufacturing plan. Except for finite inspection station classes, the limited number of inspection stations of each inspection station class is considered to solve the inspection allocation problem in this research. Rather than utilizing a constant inspection error or a specified inspection error probability distribution determined by previous observations, the inspection allocation problem is solved using relative cost models in which the inspection error model is embedded. The inspection allocation problem can then be solved by practically reflecting the inspection error when tolerances are rapidly changed to satisfy customer requirements. Since determining the optimal inspection allocation plan seems impractical as the problem size becomes quite large, two heuristic methods have been developed by considering the defective rate, manufacturing cost and earliest stage priority in this research. The performance of each method is measured in comparison with the enumeration method that generates the optimal solution. A feasible manufacturing plan can then be determined and confirmed during process planning by concurrently solving the inspection allocation problem.     

延时分辨率对超声相控阵检测性能的影响

超声相控阵检测技术是近年发展起来的一种先进的无损探伤方法,阵元间的延时分辨率是决定超声相控阵检测系统性能的关键因素,通过研究延时分辨率对相控阵检测效果的影响,可以得到延时分辨率和相关性能参数之间的对应关系,从而提高超声相控阵系统的检测性能。     

Carryover effects in multi-attribute inspection

Consider a product that has several quality attributes for inspection where the inspection of some attributes may have carryover effect(s) on subsequent inspections of other attributes. In this case, not all the attributes can be inspected on the same unit and therefore more than one unit may be required to complete one inspection cycle of all the attributes. Furthermore, if the inspection time of each attribute is considered, the number of attributes and their inspection sequence on each inspected unit may affect the time-span of an inspection cycle. In this paper, heuristic procedures are developed to find the inspection sequences of all the attributes that minimize the total number of inspected units and to balance the inspection time of each inspected unit such that the time-span of an inspection cycle is minimized. An integrated circuit card inspection example is given to illustrate the implementation of these procedures.     

A case study on measuring inspection performance for inspection job design

In the quality control system, most of the information for decision making and problem solving can be obtained by inspection activities. Therefore, the inspection work should be organized to maximize meeting the quality objectives. It has already been publicized that data obtained from measurement of inspection performance will supply an effective basis for assessment and design of the inspection station and inspection job. This paper is intended to report on a case study of measurement of inspection performance conducted for the assessment and design of an inspection job in a manufacturing company. Quality control specialists selected three groups of items having representative deficiencies under routine inspection, inspected as inspection job samples. They had individual inspectors inspect each sample to obtain data consisting of the rate of defects detected out of all the defects, and the proportion of erroneous findings in the total number of findings by each inspector. Thus they identified many problems in the inspection job to be corrected to enhance the inspection accuracy. Appropriate action was taken to remedy the situation. In the first place, the inspection job was redesigned. In the second, the method of training inspectors was reviewed and modified. As a result, the probability of defects passing the inspection undetected was greatly reduced.     

Über die Fehlerauffindbarkeit als Hauptforderung an die zerstörungsfreie Werkstoffprüfung

About the Detection of Imperfections as a Main Task for Nondestructive Testing The inspection uncertainty is identified which is a measure of the difference between the size of imperfection that has a high probability of being passed and the size of imperfection that has a high probability of being rejected by an inspection. Reduction of the inspection uncertainty is the only means by which one can reduce inspection errors as the acceptance of defective material units and the rejection of sound material units. The discussion is presented within a framework that allows a quantitative evaluation of the quality of the material units that pass an inspection and a determin ation of the rejection rate. Analysis of the causes of inspection uncertainty is essential to efficient strategies for improving nondestructive inspection capabilities.