scholarly journals Development of Testing Platform and Comparison Studies for Wood Nondestructive Testing

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Jian Li ◽  
Yiming Fang ◽  
Jiyong Tang ◽  
Hailin Feng ◽  
Xiongwei Lou
Keyword(s):  
Nondestructive Testing ◽  
Stress Wave ◽  
Virtual Instrument ◽  
Wood Properties ◽  
Time Interval ◽  
Peak Time ◽  
Testing Platform ◽  
Time Interval Measurement ◽  
Nondestructive Testing Methods

Stress wave based techniques have been developed for evaluating the quality of the wooden materials nondestructively. However the existing techniques have some shortcomings due to the significant variation of the wood properties and are now in need of updating. There are also stress wave based instruments which have been widely used for nondestructive testing of wood. But most of them are inflexible and unsuitable for the tentative studies. This paper proposed and implemented a wood nondestructive testing platform based on NI virtual instrument. Three wood nondestructive testing methods, including peak time interval measurement, cross-correlation, and spectrum analysis, were also tested on this platform with serious decay sample, early decay sample, and defect-free sample. The results show that new methods can be verified easily and the researches of wood nondestructive testing will be accelerated with the designed platform.

Application of Stress Wave Reflection Method in Nondestructive Testing of Bolt

2012 ◽  
Vol 446-449 ◽  
pp. 2229-2233 ◽  
Author(s):  
Xian Kai Bao ◽  
Yi Li
Keyword(s):  
Nondestructive Testing ◽  
Stress Wave ◽  
Wave Reflection ◽  
Reflection Method ◽  
Testing Technique ◽  
The World ◽  
History Of ◽  
Estimate Quality

Bolt has been used widely in geoengineering all over the world in recent years, the testing technique of bolt develops quickly too. This paper summarizes simply the history of bolt testing technique, describes in detail stress wave reflection method. It is useful and valuable nondestructive.Testing method is verified with several parameters which estimate quality of bolting integrity.

Experimental Study of Pile Foundation Dynamic Testing Used in the Anchor Rod Nondestructive Testing

2012 ◽  
Vol 166-169 ◽  
pp. 559-562
Author(s):  
Li Wei Zhang ◽  
Wei Shi ◽  
Yu Na Zou ◽  
De Sheng Zhu
Keyword(s):  
Nondestructive Testing ◽  
Stress Wave ◽  
Pile Foundation ◽  
Dynamic Testing ◽  
Solid Material ◽  
Wave Theory ◽  
Small Strain ◽  
Elastic Rod ◽  
Testing Technology

The dynamic testing of stress wave reflection method is an easy, economical, rapid and reliable nondestructive testing technology and has been perfected used in the pile foundation dynamic testing. Anchor rod is more in line with the wave theory of one-dimensional elastic rod than pile foundation whether to theory or the geometric solid, material, stress state and other factors. The quality of anchor rod is determined by using small strain method (hammering method) of pile foundation dynamic measurement. Four testing anchor rods with different length and integrity were made in project of "China Marine Sport School", stress wave time domain curve of anchor rod was obtained by ZK-7E portable intelligent testing of piles instrument, defect location, length of anchor rod and integrity reflected by measured waveform are consistent with the actual situation, the method using pile foundation dynamic testing technology for anchor rod nondestructive testing is proved feasible and reliable.

scholarly journals Nondestructive Testing on Ancient Wooden Components Based on Shapley Value

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Li-hong Chang ◽  
Xiao-hong Chang ◽  
Hao Chang ◽  
Wei Qian ◽  
Li-ting Cheng ◽  
...  
Keyword(s):  
Nondestructive Testing ◽  
Stress Wave ◽  
Shapley Value ◽  
Testing Methods ◽  
Internal Defects ◽  
Forecasting Models ◽  
Defect Area ◽  
Nondestructive Testing Methods ◽  
Combined Forecasting ◽  
Impedance Meter

In this study, we propose nondestructive testing methods and combined forecasting models-based stress wave and impedance measurements to obtain accurate internal defects information for wooden building components. Internal defects data for major wooden components of an ancient building in China and reverse laboratory test data on matching tree species indicated various degrees of damage on the pavilion wood structure surface and internal defects in certain pillars. The stress wave method enabled rapid acquisition of two-dimensional plots of test sections; however, the results revealed that the area of stress wave detection was greater than the actual defect area. Moreover, the impedance meter was able to determine the defect position and type in a single path, and the actual defect area was proportional to the absolute error of the drilling resistance. By distributing the errors from the two nondestructive testing methods on the basis of a Shapley value algorithm, we determined the weights of stress wave and impedance meter data in the forecasting models and established combined forecasting models that showed greater accuracy with a mean relative error of less than 6%. This method can improve the prediction accuracy of internal defects in ancient buildings and provide effective data support for practical engineering repair and reinforcement schemes.

scholarly journals A NEW APPROACH FOR ACCURACY IMPROVEMENT OF PULSED LIDAR REMOTE SENSING DATA

2018 ◽  
Vol XLII-3 ◽  
pp. 2491-2494
Author(s):  
G. Zhou ◽  
W. Huang ◽  
X. Zhou ◽  
C. He ◽  
X. Li ◽  
...  
Keyword(s):  
Remote Sensing ◽  
High Speed ◽  
Remote Sensing Data ◽  
Control Unit ◽  
Time Interval ◽  
Sampled Data ◽  
Interval Measurement ◽  
Sensing Applications ◽  
Time Interval Measurement

In remote sensing applications, the accuracy of time interval measurement is one of the most important parameters that affect the quality of pulsed lidar data. The traditional time interval measurement technique has the disadvantages of low measurement accuracy, complicated circuit structure and large error. A high-precision time interval data cannot be obtained in these traditional methods. In order to obtain higher quality of remote sensing cloud images based on the time interval measurement, a higher accuracy time interval measurement method is proposed. The method is based on charging the capacitance and sampling the change of capacitor voltage at the same time. Firstly, the approximate model of the capacitance voltage curve in the time of flight of pulse is fitted based on the sampled data. Then, the whole charging time is obtained with the fitting function. In this method, only a high-speed A/D sampler and capacitor are required in a single receiving channel, and the collected data is processed directly in the main control unit. The experimental results show that the proposed method can get error less than 3 ps. Compared with other methods, the proposed method improves the time interval accuracy by at least 20 %.

Assessment of the Integrity of Piles by Impedance Log Technique

2006 ◽  
Vol 321-323 ◽  
pp. 340-343 ◽  
Author(s):  
Jiunn Ren Lai ◽  
Chih Peng Yu ◽  
Shu Tao Liao
Keyword(s):  
Nondestructive Testing ◽  
Stress Wave ◽  
Main Idea ◽  
The Other ◽  
Testing Methods ◽  
Weak Zone ◽  
Transient Stress ◽  
Impedance Profile ◽  
Nondestructive Testing Methods ◽  
Pile Integrity

The objective of this paper is to investigate the capabilities of the Impedance Log method in profiling the geometry of a pile along its length. The main idea of this method is to introduce a transient stress wave into the pile and then utilize the reflected signals to obtain the impedance profile of the pile. Any anomaly, which results in changes in impedance, would be detected by this method. In this study, four model piles with plan defects of weak zone or neck were constructed and tested using Seismic Echo, Impulse Response, and Impedance Log pile integrity nondestructive testing methods. Results of these tests show that interpretation of signals using the Impedance Log method is more straightforward than the other two methods. It is concluded that the Impedance Log technique is a tool with high potential for evaluating the integrity of piles.

Statistical Management of Food Production Processes

2020 ◽  
pp. 30-35
Author(s):  
N.A. Jurk ◽  
Keyword(s):  
Production Process ◽  
Control Chart ◽  
Food Production ◽  
Time Interval ◽  
Bakery Products ◽  
Shewhart Control ◽  
Manufactured Products ◽  
Mnemonic Technique ◽  
The Stability

The article presents scientific research in the field of statistical controllability of the food production process using the example of bakery products for a certain time interval using statistical methods of quality management. During quality control of finished products, defects in bakery products were identified, while the initial data were recorded in the developed form of a checklist for registering defects. It has been established that the most common defect is packaging leakage. For the subsequent statistical assessment of the stability of the production process and further analysis of the causes of the identified defect, a Shewhart control chart (p-card by an alternative feature) was used, which allows you to control the quality of manufactured products by the number of defects detected. Analyzing the control chart, it was concluded that studied process is conditionally stable, and the emerging defects are random. At the last stage of the research, the Ishikawa causal diagram was used, developed using the 6M mnemonic technique, in order to identify the most significant causes that affect the occurrence of the considered defect in bakery products. A more detailed study will allow the enterprise to produce food products that meet the established requirements.

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