scholarly journals Research on the Weld Position Detection Method for Sandwich Structures from Face-Panel Side Based on Backscattered X-ray

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3198 ◽  
Author(s):  
Angang Wei ◽  
Baohua Chang ◽  
Boce Xue ◽  
Guodong Peng ◽  
Dong Du ◽  
...  
Keyword(s):  
Detection Method ◽  
Sandwich Structures ◽  
Detection System ◽  
High Reliability ◽  
Sandwich Panels ◽  
Experimental System ◽  
Maximum Absolute Error ◽  
X Ray ◽  
Position Detection ◽  
The Face

Web-core sandwich panels are a typical lightweight structure utilized in a variety of fields, such as naval, aviation, aerospace, etc. Welding is considered as an effective process to join the face panel to the core panel from the face panel side. However, it is difficult to locate the joint position (i.e., the position of core panel) due to the shielding of the face panel. This paper studies a weld position detection method based on X-ray from the face panel side for aluminum web-core sandwich panels used in aviation and naval structures. First, an experimental system was designed for weld position detection, able to quickly acquire the X-ray intensity signal backscattered by the specimen. An effective signal processing method was developed to accurately extract the characteristic value of X-ray intensity signals representing the center of the joint. Secondly, an analytical model was established to calculate and optimize the detection parameters required for detection of the weld position of a given specimen by analyzing the relationship between the backscattered X-ray intensity signal detected by the detector and the parameters of the detection system and specimen during the detection process. Finally, several experiments were carried out on a 6061 aluminum alloy specimen with a thickness of 3 mm. The experimental results demonstrate that the maximum absolute error of the detection was 0.340 mm, which is sufficiently accurate for locating the position of the joint. This paper aims to provide the technical basis for the automatic tracking of weld joints from the face panel side, required for the high-reliability manufacturing of curved sandwich structures.

Dynamic Response of Sandwich Anisotropic Flat Panels to Explosive Pressure Pulses

2001 ◽  
Author(s):  
Terry Hause ◽  
Liviu Librescu
Keyword(s):  
Dynamic Response ◽  
Detailed Analysis ◽  
Fiber Orientation ◽  
Sandwich Structures ◽  
Sandwich Panels ◽  
Core Layer ◽  
Time Dependent ◽  
Pressure Pulses ◽  
The Face ◽  
Advanced Model

Abstract This paper addresses the problem of the dynamic response in bending of flat sandwich panels exposed to time-dependent external pulses. The study is carried out in the context of an advanced model of sandwich structures that is characterized by anisotropic laminated face sheets and an orthotropic core layer. A detailed analysis of the influence of a large number of parameters associated with the particular type of pressure pulses, panel geometry, fiber orientation in the face sheets and, presence of tensile uni/biaxial edge loads is accomplished, and pertinent conclusions are outlined.

scholarly journals Research on the Weld Position Detection for the T-Joints in Web-Core Sandwich Panels Based on Eddy Current Technology

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2691
Author(s):  
Angang Wei ◽  
Baohua Chang ◽  
Fanyue Meng ◽  
Dong Du ◽  
Zandong Han
Keyword(s):  
Eddy Current ◽  
Excitation Frequency ◽  
Sandwich Panels ◽  
Outer Diameter ◽  
Technical Solution ◽  
Joint Position ◽  
T Joints ◽  
Current Technology ◽  
Position Detection ◽  
The Face

Web-core sandwich panels have gained the popularity in various fields, especially aviation and shipbuilding, etc. Penetration welding was considered as an effective process to manufacture such a structure through a T-joint. To ensure the formation quality and mechanical properties of weld, the welding torch needs to be aligned with the T-joint position. However, it is difficult to locate the T-joint position (i.e., the position of core panel) because of the shielding of the face panels. This paper investigated the detection of T-joint position from the face panel side in web-core sandwich panels based on eddy current technology. First, we designed an experimental system for the weld position detection of T-joints from the face panel side. The relationships are investigated between the characteristics of the eddy current detection signal and the primary parameters of the detection system (including excitation frequency, coil outer diameter, and lift off distance) and the T-joint (including thickness of the core panel, gap distance, and thickness of the cover panel). Corresponding experiments were carried out with variable primary parameters, and the influence mechanism of the primary parameters on the detection results in terms of sensitivity and dynamic performance was elaborated to set up the theoretical basis for the detection. Finally, weld position detection experiments were carried out on TC4 titanium alloy T-joint specimens with 3 mm-thick face panel and 5 mm-thick core panel. Results showed that the maximum detection error was 0.482 mm, and the average error was 0.234 mm. This paper provided a possible technical solution to the automatic tracking problem for the welding of T-joints in the web-core sandwich panels.

Face Detection Method Based on SSR Algorithm

2011 ◽  
Vol 128-129 ◽  
pp. 130-133
Author(s):  
Kai Song ◽  
Lei Wang ◽  
Zhi Kun Liu
Keyword(s):  
Face Detection ◽  
Template Matching ◽  
High Speed ◽  
Detection System ◽  
High Reliability ◽  
Accuracy Rate ◽  
Level Information ◽  
The Face ◽  
Feature Based ◽  
Location Detection

In order to achieve high speed and high reliability of face detection system, a feature-based template-matching algorithm to detect a key part between the two eyes used. The method is achieved through divided a filter into six rectangular. The face detection process adopts the “integral image” theory. Just calculating the information of around the eyes, eyebrows, and nose area, aspect ratio of the value of the SSR filter is set to 2.22:1 through the experimental which improved the SSR algorithm. Using the advantages of gray-level information, it has better reliability on the changes in light conditions. The experiment result shows that the accuracy rate of the standard frontal face detection is 95%; to monitoring images, the accuracy rate of the “eyes - human face” window location detection is 90%

Implication of Nonclassical Effects on Dynamic Response of Sandwich Structures Exposed to Underwater and In-Air Explosions

2007 ◽  
Vol 51 (02) ◽  
pp. 83-93
Author(s):  
Liviu Librescu ◽  
Sang-Yong Oh ◽  
Jorg Hohe
Keyword(s):  
Dynamic Response ◽  
Structural Model ◽  
Sandwich Structures ◽  
Damping Ratio ◽  
Sandwich Panels ◽  
Geometric Imperfection ◽  
The Core ◽  
The Face ◽  
Time Histories ◽  
Global And Local

A study devoted to the dynamic response of sandwich panels to underwater and in-air explosions is presented. The study is carried out in the context of a geometrically nonlinear model of sandwich structures featuring anisotropic laminated face sheets and a transversely compressible orthotropic core. The unsteady pressure generated by the explosion and acting on the face of the sandwich panel includes the effect of the pressure wave transmission through the core. Its implications on the structural time-histories as corresponding to the underwater and in-air explosions are put into evidence. The effects of the transverse core compressibility on dynamic response are highlighted. In this sense, one of its major implications is the possibility to capture interactively the global and local (wrinkling) dynamic response of the panel. It is shown that implementation of the structural tailoring technique in the face sheets can constitute an important mechanism for enhancing the dynamic load-carrying capacity of sandwich panels when exposed to blast pulses. Effects of the core, the composite architecture of face sheets, orthotropy of the material of the core, geometrical non-linearities, initial geometric imperfection, and the damping ratio are investigated, and their implications for the dynamic response are highlighted. The comprehensive structural model considered in conjunction with the time-dependent loads generated by the underwater and in-air explosions, and the results obtained in this context, are expected to contribute to a better understanding of the response behavior and to be instrumental toward a better design of these structures.

scholarly journals Sistem Deteksi Wajah Pada Kamera Realtime dengan menggunakan Metode Viola Jones

2019 ◽  
Vol 8 (1) ◽  
pp. 30-37
Author(s):  
Rizka Eka Putri ◽  
Tekad Matulatan ◽  
Nurul Hayaty
Keyword(s):  
Detection Method ◽  
Detection System ◽  
Cascade Classifier ◽  
Integral Image ◽  
Main Method ◽  
Advantages And Disadvantages ◽  
Haar Feature ◽  
The Face ◽  
The Mind ◽  
Speed And Accuracy

In general, human are given the mind and mind to be able to determine or be able to didtinguish individuals who appear either human, animal, plant, and other objects that are known or unknown. And it is possible for human to recognize these object from their sight and from their brain memory. Especially on the human face, human can recognize whether the object is human or not human, and can recognize the object very well through his own eyes.face detection system in human becomes very important in the development of science of digital image processing. The research has been done with many advantages and disadvantages. From a face many information features that can be read, such as eyes, nose, and mouth. The detection system uses Viola Jones method as an object detection method. The Viola Jones method is known to have considerable Speed and accuracy as it combines several concepts (Haar feature, Integral image, Adaboost, Cascade classifier) into a main method for detecting objects.Based on tests conducted on face identification under conditions that may affect face detection results, the results show an accuracy of 67,6 % to detect the face.

A Modular X-Ray Detection System

2019 ◽  
Author(s):  
Robert Viola ◽  
Keyword(s):  
Detection System ◽  
X Ray

Image detection and parameterization for different components in cross-sections of radial tires

2021 ◽  
pp. 095440702110236
Author(s):  
Chen Liu ◽  
Yude Dong ◽  
Yanli Wei ◽  
Jiangtao Wang ◽  
Hongling Li
Keyword(s):  
Image Processing ◽  
Digital Image Processing ◽  
Cross Sections ◽  
Digital Image ◽  
Detection Method ◽  
Detection System ◽  
Practical Significance ◽  
Vehicle Safety ◽  
Wire Steel ◽  
Good Detection

The internal structure analysis of radial tires is of great significance to improve vehicle safety and during tire research. In order to perform the digital analysis and detection of the internal composition in radial tire cross-sections, a detection method based on digital image processing was proposed. The research was carried out as follows: (a) the distribution detection and parametric analysis of the bead wire, steel belt, and carcass in the tire section were performed by means of digital image processing, connected domain extraction, and Hough transform; (b) using the angle of location distribution and area relationship, the detection data were optimized through coordinate and quantity relationship constraints; (c) a detection system for tire cross-section components was designed using the MATLAB platform. Our experimental results showed that this method displayed a good detection performance, and important practical significance for the research and manufacture of tires.

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