Thermal Wave Image Reconstruction of Bonding Defects in Missile Engine Shell

2011 ◽  
Vol 58-60 ◽  
pp. 1344-1349 ◽  
Author(s):  
Wei Zhang ◽  
Zheng Wei Qiu ◽  
Dong Dong Wang ◽  
Zheng Wei Yang ◽  
Lu Zhu
Keyword(s):  
3D Reconstruction ◽  
Volume Rendering ◽  
Thermal Wave ◽  
High Frequency ◽  
Clustering Algorithm ◽  
Space Structure ◽  
Defect Size ◽  
Filtering Method ◽  
Quantitative Identification ◽  
Wave Image

Defects in the specimen of missile engine shell was detected by thermal wave image technology in this paper. In order to gain intuitionistic and accurate space structure image of the detected object, subtracting background and high-frequency emphasized filtering method were used to enhance the image quality. Then the defect was segmented from the background using particle swarm fuzzy clustering algorithm, while the defect size and depth were identified quantitatively. On this basis, 3D reconstruction of the defect by thermal wave image was recognized by Volume Rendering method. The results show that the precision of the defect quantitative identification is higher, and 3D reconstruction result is well, which help us to observe the location and size of defects intuitionisticly.

Improved Clustering Algorithm of Spatial Data Structure Based on Matlab Simulink

2014 ◽  
Vol 608-609 ◽  
pp. 98-102
Author(s):  
Shan Mei Xiong ◽  
Ru Lian Wu ◽  
Hui Wang
Keyword(s):  
Spatial Data ◽  
Clustering Algorithm ◽  
Geographical Location ◽  
Calculation Model ◽  
Space Structure ◽  
Urban Tourism ◽  
Programming Algorithm ◽  
Tourism Destination ◽  
Consumption Structure ◽  
Matlab Programming

This paper has introduced the clustering algorithm into the model of urban tourism destination consumption structure, and has used MATLAB programming algorithm to improve the calculation model of consumption structure for tourism destination, which has obtained the spatial data model of the consumption structure. The model roundly considers the influence of geographical location, cultural factors, political factors and economic factors, and it establishes new clustering algorithm model with four coefficients, and has realized the algorithm by the use of MATLAB programming. Finally, the consumption structure of the same destination in different provinces is calculated by using the spatial system model, which has obtained the calculation curve of consumption space structure and the clustering results, and has provided technical reference for the research on consumption of urban tourism destination.

Fast Volume Rendering Techniques for 3D Reconstruction of Geological Objects

2012 ◽  
Vol 182-183 ◽  
pp. 1343-1346
Author(s):  
De Wen Seng ◽  
Da Qing Li
Keyword(s):  
3D Reconstruction ◽  
Volume Rendering ◽  
Spatial Data ◽  
Real Data ◽  
Tree Structure ◽  
Marching Cubes ◽  
Geological Data ◽  
Iron Mine ◽  
Effectiveness And Efficiency ◽  
Rendering Techniques

The procedure of volume rendering techniques is introduced. The principles and methods of two kinds of different volume rendering techniques of 3D spatial data are discussed. Application of Marching Cubes (MC) algorithm in the modeling of geological objects is given. This algorithm is modified and improved in several aspects. The asymptotic decider algorithm is employed to solve the ambiguity problem and oct-tree structure is used to reduce the number of polygons generated, which will increases the efficiency of the algorithm. The improved algorithm is applied to real geological data obtained from an iron mine in China. Real data derived from an iron mine of China demonstrates the effectiveness and efficiency of the system and the algorithms.

A Thin Cloud Removal Method for Optical Image Based on Improved Homomorphism Filtering

2014 ◽  
Vol 618 ◽  
pp. 519-522
Author(s):  
Guang Yu ◽  
Wen Bang Sun ◽  
Gang Liu ◽  
Mai Yu Zhou
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Frequency Component ◽  
Frequency Region ◽  
High Frequency Region ◽  
Filtering Method ◽  
Thin Cloud ◽  
Cloud Removal ◽  
Thin Cloud Removal ◽  
Image Definition

Optical remote image is affected by thin cloud inevitably, which debases image definition. Traditional homomorphism filtering frequently used in thin cloud removing has affect on the cloud in low frequency region, but is not effective for those in high frequency region. An improved homomorphism filtering method is proposed on the basis of statistical characters of image information. Instead of the filtering in frequency field, it isolates the low frequency component of the image representing cloud information with calculating neighborhood average in spatial field. Then, the filtered image is enhanced based on rough set. The experiment results show that the proposed method compared to traditional methods can obtain good results and performs faster.

Damping and Resonance Characteristics of Thermal Waves

1992 ◽  
Vol 59 (4) ◽  
pp. 862-867 ◽  
Author(s):  
Da Yu Tzou
Keyword(s):  
Resonance Frequency ◽  
Thermal Wave ◽  
High Frequency ◽  
Wave Speed ◽  
Thermal Waves ◽  
Resonance Behavior ◽  
Engineering Materials

Amplification of thermal waves in response to high-frequency excitations is studied in this work. The resonance behavior is explored along with the underdamped behavior in thermal wave oscillations. In transition from an overdamped to an underdamped wave behavior, the relaxation distance is found to dominate the process. A relationship between the resonance frequency and the thermal wave speed is derived. The emphasis is placed on the frequency approach determining the thermal wave speed in engineering materials.

Numerical Analysis for Thermal Wave NDT of Debonding Defect of Coating on the Matrix of the Composite Materials

2012 ◽  
Vol 174-177 ◽  
pp. 1357-1362
Author(s):  
Wei Zhang ◽  
Qi Ke Li ◽  
Zheng Wei Yang
Keyword(s):  
Heat Transfer ◽  
Composite Materials ◽  
Thermal Wave ◽  
Simulation Method ◽  
Heat Transfer Process ◽  
Defect Size ◽  
Wave Detection ◽  
Factors Influencing ◽  
The Matrix ◽  
Simulation Results

For the disadvantages of the traditional NDT methods for coating defects, Thermal Wave Nondestructive Testing (TWNDT) technology was used to detect coating debonding defect on composite Materials matrix. Numerical simulation method was used to simulate the heat transfer process of thermal wave in the coating material with defects. The factors influencing the testing sensitivity were in-depth studied, including the debonding defect size and coating thickness. Simulation results show that: TWNDT technology can quickly and efficiently identify the size of the coating debonding defects, while the thickness of the coating is an important factor influencing the inspection sensitivity for the thermal wave detection.

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