Acoustic Non-Destructive Testing Technology in Concrete Bridge Inspection and Pile Foundation Detection

This article takes the actual construction project of a certain concrete bridge project as an example to analyze the application of acoustic non-destructive testing technology in its detection.It includes an overview of a certain bridge construction project studied and acoustic non-destructive testing technology and the application of acoustic non-destructive testing technology in actual testing.This analysis hopes to provide some guidelines for acoustic non-destructive testing of modern concrete bridge projects.

Discussion on the Status Quo of Non-Destructive Testing Technology in Highway Engineering and Strategies of Improving the Quality of Testing

Highway test and detection technology play a very important role in controlling the quality of road and bridge engineering and improving the maintenance of roads and bridges.The study of highway bridge test detection technology is both theoretically and practically useful.Road and bridge test and detection is a complicated task.With the development of science and technology,highway and bridge engineering test and detection technology has also made great progress.The continuous improvement of test and detection technology has brought good social benefits to road and bridge construction.This article discusses the problems in test and detection technology of highway bridges and how to improve the quality of test and detection.

Non-Destructive Testing of Structures Using Optical and Other Methods: A Review

Non-destructive testing (NDT) of structures is one of the most important tasksof the proper maintenance and diagnosis of machines and constructions structuralcondition. NDT methods contribute to the damage tolerance philosophy used in theaircraft design methodology as well as many other operation and maintenance programsof machinery and constructions. The following study is focusing on overviewing animportant group of NDT methods: the optical and other ones, which found broadapplicability in scientific and industrial studies nowadays. The paper discusses theselected most widely applicable methods, namely, visual testing, ultrasonic testing,radiographic testing, infrared thermography as well as electronic speckle patterninterferometry and shearographic testing. Besides the basic principles of testing usingthese methods, their potential applications in various industrial and technologicalbranches are broadly discussed. The analysis as categorization of the NDT methodsprovided in this paper may help in selection of such methods in diagnosis of varioustypes of structures and defects and damage occurring in these structures.

NON-DESTRUCTIVE PAVEMENT LAYER THICKNESS MEASUREMENT USING EMPIRICAL MODE DECOMPOSITION WITH GPR

Ground Penetrating Radar(GPR) is an effective Non-Destructive Testing(NDT) technique for highway pavement surveys, which is able to acquire continuous pavement data compared with traditional core drilling method. In this study, we proposed an accurate and efficient method to estimate the thickness of each pavement layer using an air-coupled GPR system. For this work, the main difficulties are estimating each pavement layer's time delay and dielectric constant. We first give the basic signal model for pavement evaluation, and then present an Intrinsic Mode Functions(IMFs) product detector to determine each pavement layer's time delay. This method is based on Empirical Mode Decomposition(EMD), which is an adaptive signal decomposition procedure and proved to be suitable for suppressing noises in GPR signal. The dielectric constant was determined by metal reflection measurement. The laboratory and highway experiments illustrate that the proposed thickness estimation method yields reasonable result, thus meets the requirements of practical highway pavement survey with massive GPR data.

Evaluation of internal void related defects in reinforced concrete slab using electromagnetic wave properties

This study aims to develop a damage-detection algorithm based on the electromagnetic wave properties inside a reinforced concrete structure.The proposed method involves employing two algorithms based on data measured using ground-penetrating radar—a common electromagnetic wave method in civil engineering.The possible defect area was identified based on the energy dissipated by the damage in the frequency-wavenumber domain,with the damage localized using the calculated relative permittivity of the measurements.The proposed method was verified through a finite difference time-domain-based numerical analysis and a testing slab with artificial damage.As a result of verification,the proposed method quickly identified the presence of damage inside the concrete,especially for honeycomb-like defects located at the top of the rebar.This study has practical significance in scanning structures over a large area more quickly than other non-destructive testing methods,such as ultrasonic methods.

建筑工程结构混凝土检测方法的选择与分析

结构混凝土是混凝土工程中的重要表现形式。结构混凝土因受各项物理力学、耐久性等要求,在其质量评定过程中难以采用最直接的钻芯法进行质量评价,急需找到最佳的质量评价方法。笔者阐述了几种无损检测技术在结构混凝土质量评价中的适用情况,以便在不同的结构尺寸、钢筋分布、结构工况等情况下能够快速、准确地选择所适用的无损检测方法。

Successes and challenges in non-destructive testing of aircraft composite structures

Composite materials are increasingly used in the aerospace industry.To fully realise the weight saving potential along with superior mechanical properties that composites offer in safety critical applications,reliable Non-Destructive Testing(NDT)methods are required to prevent catastrophic failures.This paper will review the state of the art in the field and point to highlight the success and challenges that different NDT methods are faced to evaluate the integrity of critical aerospace composites.The focus will be on advanced certificated NDT methods for damage detection and characterization in composite laminates for use in the aircraft primary and secondary structures.

Enhancing Production Efficiency of Oil and Natural Gas Pipes Using Microwave Technology

The research reported in this paper aims at developing means of Non Destructive testing (NDT) to increase the line efficiency of pipe production in oil and natural gas pipe manufacturing plants using the Standard Allowed Minutes (SAM) method. Existing line production stations encounter difficulties in maintaining the recommended testing speed of smaller diameter pipe, due to limitations in the Visual Inspection (VI) station. We propose to implement one additional technique which will prevent the decline of line efficiency in a pipe production factory. The range of diameters identified as a problem in this research is from 254 mm to 762 mm. Microwave techniques are expected to improve the line efficiency by increasing the production of the plant. This happens as a consequence of maintaining the production rates of the identified pipe diameters, so that they equal the production output of the larger pipe diameters. We analyze the velocity traveled by the pipe through Radiographic Testing (RT) according to the VI output (production). The RT velocity is decreased for the diameters identified above, in order to maintain quality control and cover the shortcoming of the VI. The number of pipes produced is computed during shift hours of the factory and pipe lengths of the forming department are determined. We compare the output (production) of a series of NDT line stations with and without the microwave technique for the first of the three pipe cases considered in this study, classified as perfect pipe (PP), repair pipe (RP) and scrap pipe (SP). The velocity of RT stations analyzed in the paper ranges from 50 mm/s for larger diameter pipe, and decline to 16.667 mm/s for the identified diameters. The analytical calculations of line output (production) and line efficiency demonstrate the solution of this velocity problem after the microwave technique is introduced. It demonstrates that an economical and precise methodology to extend the production capability of the pipe plant has been determined.

Numerical Simulation of Non-destructive Testing of Stainless Steel Composites Plate by Infrared Thermography

The non-destructive testing(NDT)of debonding in stainless steel composites plate(SSCP)is performed by infrared thermography,finite element analysis(FEA)software ANSYS is taken as the simulative tool,and 2D simulative model has been set up to investigate effect of the thickness of coating and/or substrate on the detectibility of debonging in SSCPs.Two parameters,namely the maximum defect temperature difference and defect appearing index,are defined to evaluate the detectivity of defects,and their computational methods and formulas are given respectively.The preliminary changing tendency of the maximum defect temperature difference and defect appearing index with the thickness of coating and/or substrate is found by numerical simulation.

光谱技术及电子感官系统在食源性致病菌无损检测中的应用

无损检测是在不破坏被检样品的前提下,进行检测分析的一种方法和技术,具有非侵入性。采用无损检测方法对食源性致病菌进行快速检测对食品安全具有重大意义。该文介绍和分析3大无损检测技术(近红外光谱技术、高光谱技术和电子感官技术)的基本原理及其在食品常见致病菌检测中的应用及最新研究进展,为无损检测技术在食品中的进一步应用提供参考。

无损检测技术在承压设备接头检测中的应用研究

由于承压类设备输送物质的特殊性,接头部位非常容易出现松动。针对传统的接头检测方法受场地影响存在劳动强度大、检测效率低、结果可信度较低,非常容易引起泄漏或爆炸等问题,本文通过对传统的接头检测方法进行分析,提出了一种基于无损检测技术的承压设备接头检测方案,对多种无损检测技术进行了介绍,对硬件模块进行了设计,经现场应用表明本次设计方案检测新技术检测效率高、效果好、系统误判率≤0.30%,取得良好的应用效果。

基于文献计量学的红外无损检测技术进展与趋势分析

红外检测(infrared testing,IRT)近年来得到了极速增长,围绕IRT的技术成为各个领域的重要研究方向。本文梳理分析了国内外多年来关于IRT技术的文献,总结了该领域研究方向国内外未来研究热点。基于web of science(WOS)核心合集数据库,运用CiteSpace数据挖掘及分析平台对这一研究领域的最新进展进行深入分析。对发文数量、国家、作者、研究机构、关键词、被引文献及期刊进行多维度探讨,力求全面剖析此领域研究热点及发展趋势。本文重点跟踪了金属部件缺陷检测、复合材料缺陷检测与红外图像绝缘体检测技术研究方向。

无人机在高层住宅外立面现场检测中的应用

房屋的长期使用导致建筑结构、材料老化,产生安全隐患;特别是高层建筑外立面脱落,极易引发安全事故,威胁人们的生命财产安全。因此,对建筑外立面特别是高层住宅外立面的整治愈发呈现需求量大、紧迫性高的趋势。文章结合实践经验,对无人机在高层住宅外立面现场检测中的操作方法及关键技术点进行总结;对比传统检测技术,分析其全面、高效的技术优势;指出应重视防水、防尘、防电磁干扰、镜头及电池维护等日常维护保养工作。

石油管道内缺陷无损检测技术的研究现状

对目前输油输气管线内缺陷检测的最新技术及相关研究做了综述;逐一对漏磁探伤、超声波类检测、脉冲涡流检测、光学原理类和射线照相类检测等方法做了较全面的介绍,包括工作原理、优势、使用范围及其局限性;对管道内检测技术的存在问题和发展趋势做了简述。

固体火箭发动机装药缺陷原因分析及无损检测方法的研究

分析了固体火箭发动机的装药缺陷及其产生原因,阐述了装药缺陷对固体发动机可靠稳定工作的影响与危害,进而强调了对装药进行无损检测的重要性和必要性;随即介绍了装药无损检测技术的现状,列举比较了几种常规检测方法,为固体火箭发动机无损检测领域的应用研究提供了借鉴与参考.

无损检测及其新技术

介绍了当前无损检测领域中常用技术,如超声、射线、渗透、涡流、磁粉等常规无损检测技术,以及迅速发展并受人们普遍关注的超声相控阵、激光、红外、微波等无损检测新技术,包括其基本原理、技术特点及应用范围.

金属管道超声波无损检测方法的研究

在科学技术快速发展的时代,金属管道的检测技术也需要不断进步,本文所探讨的基于超声波无损检测方法,利用超声波技术来实现对金属管道中的裂纹损伤进行实时检测,无需在工程停止工作中进行检测,在正常工作状态下完全可以进行金属管道的无损检测,可以提高生产效率。

Current Trends and Perspectives of Detection and Location for Buried Non-Metallic Pipelines

Buried pipelines are an essential component of the urban infrastructure of modern cities.Traditional buried pipes are mainly made of metal materials.With the development of material science and technology in recent years,non-metallic pipes,such as plastic pipes,ceramic pipes,and concrete pipes,are increasingly taking the place of pipes made from metal in various pipeline networks such as water supply,drainage,heat,industry,oil,and gas.The location technologies for the location of the buried metal pipeline have become mature,but detection and location technologies for the non-metallic pipelines are still developing.In this paper,current trends and future perspectives of detection and location of buried non-metallic pipelines are summarized.Initially,this paper reviews and analyzes electromagnetic induction technologies,electromagnetic wave technologies,and other physics-based technologies.It then focuses on acoustic detection and location technologies,and finally introduces emerging technologies.Then the technical characteristics of each detection and location method have been compared,with their strengths and weaknesses identified.The current trends and future perspectives of each buried non-metallic pipeline detection and location technology have also been defined.Finally,some suggestions for the future development of buried non-metallic pipeline detection and location technologies are provided.

Predicting Concrete Compressive Strength Using Deep Convolutional Neural Network Based on Image Characteristics

In this study,we examined the efficacy of a deep convolutional neural network(DCNN)in recognizing concrete surface images and predicting the compressive strength of concrete.A digital single-lens reflex(DSLR)camera and microscope were simultaneously used to obtain concrete surface images used as the input data for the DCNN.Thereafter,training,validation,and testing of the DCNNs were performed based on the DSLR camera and microscope image data.Results of the analysis indicated that the DCNN employing DSLR image data achieved a relatively higher accuracy.The accuracy of the DSLR-derived image data was attributed to the relatively wider range of the DSLR camera,which was beneficial for extracting a larger number of features.Moreover,the DSLR camera procured more realistic images than the microscope.Thus,when the compressive strength of concrete was evaluated using the DCNN employing a DSLR camera,time and cost were reduced,whereas the usefulness increased.Furthermore,an indirect comparison of the accuracy of the DCNN with that of existing non-destructive methods for evaluating the strength of concrete proved the reliability of DCNN-derived concrete strength predictions.In addition,it was determined that the DCNN used for concrete strength evaluations in this study can be further expanded to detect and evaluate various deteriorative factors that affect the durability of structures,such as salt damage,carbonation,sulfation,corrosion,and freezing-thawing.

Concrete damage diagnosed using the non-classical nonlinear acoustic method

It is known that the strength of concrete is seriously affected by damage and cracking. In this paper, six concrete samples under different damage levels are studied. The experimental results show a linear dependence of the resonance frequency shift on strain amplitude at the fundamental frequency, and approximate quadratic dependence of the am- plitudes of the second and third harmonics on strain amplitude at the fundamental frequency as well. In addition, the amplitude of the third harmonics is shown to increase with the increase of damage level, which is even higher than that of the second harmonics in samples with higher damage levels. These are three properties of non-classical nonlinear acoustics. The nonlinear parameters increase from 106 to 108 with damage level, and are more sensitive to the damage level of the concrete than the linear parameters obtained by using traditional acoustics methods. So, this method based on non-classical nonlinear acoustics may provide a better means of non-destructive testing （NDT） of concrete and other porous materials.