锚杆承载力的灰色系统预测法

声波测试技术应用于锚固工程的无损检测中 ,其基本原理是采用动力瞬态激振使锚杆引起弹性振动 ,通过测定锚杆的振动响应来估计和推断锚杆的承载力。通过锚杆质量动测法的试验 ,就锚杆承载力的灰色系统预测方法进行了讨论 ,并与锚杆抗拔检测结果进行了对比。运用灰色系统的锚杆质量检测可取得良好的效果。     

锚杆承载力的灰色系统预测法

声波测试技术应用于锚固工程的无损检测中，其基本原理是采用动力瞬态激振使锚杆引起弹性振动，通过测定锚杆的振动响应来估计和推断锚杆的承栽力。通过锚杆质量动测法的试验，就锚杆承载力的灰色系统预测方法进行了讨论，并与锚杆抗拔检测结果进行了对比。运用灰色系统的锚杆质量检测可取得良好的效果。     

锚杆极限承载力的人工神经网络预测

岩石声波测试技术应用于锚固工程的无损检测中，其基本原理是采用动力瞬态激振使描杆引起弹性振动，通过测定锚杆的振动响应来估计和推断锚杆的极限承载力。将人工神经网络这类非线性动力学系统运用于该灰色系统的预测，可取得良好的效果。     

锚固系统的质量管理与检测技术研究

岩石声波测试技术应用于锚固工程的无损检测中,其基本原理是采用动力瞬态激振使锚杆引起弹性振动,通过测定锚杆的振动响应来估计和推断锚杆中的缺陷。波动方程的有限元数值解表明,在锚杆灌浆体内部缺陷的探测中可用声速、幅值、波形等声参数作为判断的依据。人工神经网络这类非线性动力学系统运用于该灰色系统的质量预测可取得良好的效果。     

基于小波神经网络的锚杆锚固质量分析

敲击-回波法正广泛应用于锚杆锚固质量的无损检测中，该方法中存在诸多的影响因素，因此很难直接根据实测的时程曲线对锚杆锚固质量进行准确的人工判读。首先，将小波分析和人工神经网络结合起来，采用数值模拟得到锚杆外端部的动态响应并进行小波分析，从各分量中提取特征向量；然后，将这些特征向量输入人工神经网络进行训练。分析结果表明，训练后的神经网络能根据实测信号的特征向量对锚杆锚固质量进行智能化分类。     

完整锚杆横向动力响应问题的求解与分析

锚杆锚固质量两个主要衡量指标是锚固状态和锚固力。锚固状态是指锚杆施工后的锚固段长度、自由段长度、密实度和施工缺陷等;锚固力指现场拉拔试验过程中临界破坏点的拉拔力,又称极限抗拔力。利用振动波传播具有的许多独特性质,可以在锚杆表面人工激发应力波来探测锚杆体系内部的结构和性质,以此来判断锚杆的锚固状态。锚杆的无损检测研究已提出多年,但研究方向主要为纵向振动,有关锚杆系统的横向动力响应很少有人提及。建立了锚杆体系横向动力响应的理论模型,推导了完整锚杆的理论半解析计算公式,在此基础探讨了锚杆系统横向振动随锚杆长度、激振力作用时间等变化的一些规律。     

预应力锚杆张力无损检测方法初探

提出利用振动响应特征来检测锚杆预应力张力的无损检测技术方法,通过数值分析和试验验证,初探了检测方法的合理性和可行性.     

低应变应力波反射法在锚杆无损检测中的应用

简单介绍了国内开展锚杆无损检测的概况,论述了低应变反射波法进行锚杆无损检测的基本原理及其在锚杆无损检测中应用的现状,标准锚杆的制作、试验、锚杆缺陷分析判别的基本原则和方法,以供参考.     

锚固质量的无损检测技术

基于锚固体系的锚杆动力学及应力波运动学理论,研究了锚固体系的振动特征和锚固体系中声频应力波传播的能量衰减规律,进而提出快速普查检测锚杆锚固状态的声频应力波法：介绍了依据拉拔曲线转折段两边割线的交点法确定锚杆锚固力的无损拉拔检测技术原理,并实际应用于潘集第一煤矿巷道锚杆支护施工质量的检测。     

锚杆锚固质量无损检测技术

提出锚杆锚固质量无损检测的数学物理模型、检测方法和评价方法,重点阐述声波反射法在锚杆锚固质量无损检测中的应用及其效果。     

地质雷达在混凝土完整性检测中的应用

探地雷达作为近10几年来新兴起来的进行地下探测和混凝土无损检测的一种高新技术,具有操作简单,结果稳定的优点。采用劳雷SIR-20型地质雷达,对某轨道梁的混凝土完整性进行检测,同时与完好梁的检测结果进行对比,该梁混凝土完整性较好。     

Non-destructive detection of surface-bond defects in carbon composite-strengthened concrete structures

For almost 15 years, carbon fibre-reinforced polymer (CFRP) plates and sheets have been used for strengthening and repair of civil engineering structures. CFRP plates were applied to upgrade structures for change in use or increasing traffic load. CFRP laminates have also been used to repair deteriorated structures such as multi-storey parking or bridges. The execution quality and condition of the strengthening measure in terms of bond integrity were neither monitored nor tested systematically. Inspectors eventually applied simple hammer knocking during regular main inspection for subjective noise distinction as a measure for eventual insufficient bond. This paper presents the feasibility and the limitations of low-frequency transversal ultrasonic waves with dry-coupling point-contact sensors for inspection and defect detection between CFRP laminate and concrete surfaces. The German Centre of Competence in Civil Engineering (DIBt) has initiated a national research project [Helmerich et al. (2012). Condition analysis of bonded CFRP-applications on concrete structures by means of non-destructive testing [in German: Zustandsuntersuchung von CFK-Klebeverstärkungen an Betonbauteilen mittels zerstörungsfreier Prüfung (ZfP)]. Final, internal project report], carried out at the Federal Institute for Materials Research and Testing (BAM), Germany. The aim of the project was to present a potential non-destructive testing method for bond defect detection as a measure for the durability of the strengthening system more than 10 years after application.     

锚杆动测问题的解析解

岩石声波测试技术应用于锚固工程的无损检测中，其基本原理是采用动力瞬态激振使锚杆引起弹性振动，通过测定锚杆的振动响应来估计和推断锚杆中的缺陷。应用弹性动力学的基本理论，建立了锚杆动测问题的物理模型，在力学上表现为给定扰动源信息及边界条件、初始条件，建立描述介质运动的支配方程，归结为双曲型或双曲—扩散型方程的初值或初值—边值问题，由此求解其动力响应，推导了一维非齐次波动方程在有界域情况下的解析解。     

钢丝缺陷磁致伸缩导波检测信号特性实验研究

缆索体系作为现代土木建设广泛应用结构之一,作为主要承载部件对整体结构的安全性和使用寿命至关重要。磁致伸缩导波无损检测技术在缆索损伤和腐蚀检测方面具有检测长度大,覆盖结构区域广等优势,逐渐成为应用广泛的缆索新型无损检测方法。磁致伸缩导波无损检测技术在损伤和腐蚀的定性问题上已经比较稳定,缺陷尺寸和缺陷回波的定量关系与诸多因素有关,本文对缆索的基本单元高强钢丝的缺口检测信号进行了实验研究,得到缺陷回波反射系数与钢丝缺陷截面损失率的关系,发现其与抛物线非常近似;本研究为钢丝及钢丝拉索的损伤和腐蚀磁致伸缩导波无损检测的定量评价提供了基础。     

锚杆低应变动测的数值研究

岩石声波测试技术应用于锚固工程的无损检测中，其基本原理是采用动力瞬态激振，使锚杆引起弹性振动，通过测定锚杆的振动响应来估计和推断锚杆中的缺陷。该方法在力学上表现为给定扰动源信息及边界、初始条件，建立描述介质运动的支配方程，并由此求解其动力响应，通常归结为双曲型或双曲-扩散型方程的初值或初值-边值问题．波动方程的有限元数值解表明，在锚杆灌浆体内部缺陷的探测中，可用声速、幅值、波形等声参数作为判断的依据，若再加上在缺陷处的频谱畸变参数，则可使判断更为可靠。     

Corrosion damage assessment method for steel guardrail post roots

Steel guardrail posts are typically used on the highway system of Japan, but these can experience the corrosion damage at their root near the road surface. This damage may be particularly severe in the seaside areas or regions that experience cold weather and employ salt as a deicing agent. Therefore, this study aimed to develop a non-destructive way of estimating the extent of corrosion in the guardrail post roots. Particularly, 11 test specimens were parametrically designed to investigate the efficiency of using the impact vibration mode to assess the corrosion damage. The corrosion angle, range and thickness at the post root were the main parameters. Meanwhile, a parametric FEM analysis was executed as well to analyze the vibration behavior, the stiffness and the load-carrying capacity. In general, the study reveals that the high-order vibration modes are sensitive to the corrosion damage at the guardrail post roots, and based on this, an impact vibration method for assessing the corrosion damage was proposed.     

Monitoring the structural integrity of a flexible riser during a full-scale fatigue test

Flexible risers are presently seen as an attractive alternative to their rigid counterparts in the offshore oil exploration industry, mainly because of their relatively simpler mounting and transportation. However, the complex multi-layered structure which guarantees high flexural compliance is not favorable for inspection with most non-destructive testing (NDT) techniques, which makes structural integrity evaluation difficult. Initial efforts concentrated on the search for a single technique which would ensure reliable detection of armor failure, but recent studies have shown that the safest approach may be to take advantage of the redundancy obtained when different instruments are combined. This work presents results of a full-scale dynamic loading test of a 6 m-long section of a flexible pipe with end-fittings which was instrumented with a range of sensors. Of these, measurements of torsional angle variation, axial displacement and Acoustic Emission were selected for a direct comparison. A detection pattern is observed during forced rupture of the wires of one of the outer armor layers, and reliable identification of events is possible when information from the three techniques is combined.     

应用无损检测技术评价沥青路面施工离析

介绍了评定沥青路面离析和不均匀性的无破损检测方法,分析了造成沥青混合料出现离析和不均匀性的原因,结果表明,采用无损检测技术,可以快速、准确地对路面施工质量进行定量的评价。