In-situ monitoring and ex-situ elasticity mapping of laser induced metal melting pool using ultrasound: Numerical and experimental approaches

This paper studies the feature extraction and middle-level expression of Convolutional Neural Network (CNN) convolutional layer glass broken and cracked at the scene of road traffic accident. The image pyramid is constructed and used as the input of the CNN model, and the convolutional layer road traffic accident scene glass breakage and crack characteristics at each scale in the pyramid are extracted separately, and then the depth descriptors at different image scales are extracted. In order to improve the discriminative power of the depth descriptor, Hellinger kernel and Principal Component Analysis (PCA) are used to perform nonlinear and linear transformations. Two aggregation strategies based on depth descriptors are proposed to form a global image representation. The classification experiment of the data set shows that Hellinger kernel, PCA transformation, and two aggregation strategies are all conducive to improving the classification accuracy. In addition, the convolutional layer road traffic accident scene glass breaking and crack feature coding can obtain better classification performance than the fully connected layer feature. We conducted dynamic impact tests on plate glass and Polyvinyl Butyral- (PVB-) laminated glass under different boundary conditions and studied the crack propagation and failure process of the glass under different impact speeds. The results show that there are radial cracks and circular cracks on the glass specimens under the impact load; the glass specimens show partial damage under high-speed impact and the characteristics of glass breaking and cracks at the scene of road traffic accidents; the four-frame plate glass is supported by sharp dagger-like fragments. This paper compares the energy absorption of glass specimens under different boundary conditions. The results show that the energy absorption effect of the four-point supporting glass specimen is generally stronger than that of the four-frame supporting glass.

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Feature Extraction of Broken Glass Cracks in Road Traffic Accident Site Based on Deep Learning

There are many changes in the automotive industry, today. All aluminum sheets used in the automotive body must have good weldability. In this article, we will test the spot welding on 6 types of 5XXX and 6XXX aluminum sheets. These sheets have been selected as the best sheet suitable for the automotive body after welding test on all sheets. This test was examined by ultrasound. The signals obtained from the ultrasound wave test do not have accurate results for better sheet determination. For this purpose, signal processing was performed on the obtained signals in order to detect sheet defect. By simulating these sheets, a comparison is made between the experimental test and the simulation, which can be used to make the best decision about the chosen sheets. The status charts of these sheets have been reviewed and it is easy to select the sheets that have been tested in the shortest time. Generally, findings indicated that the best suitable sheets in automotive body are type of 5XXX aluminum sheets.

Analysis and Examination of Aluminum Sheets Suitable for Automotion Body: Ultrasonic Testing, Signal Processing, Simulation

The basic defects of turbines in the water, oil and aerospace industries are very obvious. Turbines play a key role by rotating the impeller. In some turbine engines, impellers are used instead of axial compressors, and the impeller play a key role in investigating defects that can increase its performance and life of the turbine. The blades have different dimensions and shapes and are installed on the impeller by bolt and nut connections. The shape, dimensions and number of blades vary depending on the power required. In the present study, corrosion defect on the turbine impeller was performed with one of the non-destructive tests, which was an ultrasonic test. The defect is considered to be corrosion, which occurs mostly in turbines in the oil and water industries, and its examination in non-destructive testing will be an attractive challenge. Corrosion defects occur with work and rotational performance of the impellers long-term. Measuring the diameter by ultrasound, which is a new method in this test, the amount of corrosion will be detected. In this article, 20 turbines with defective blades were tested. The defect was simulated by Comsol software to prove the experimental work. According to various tests about the size of the defect, the new solution can determine the approximate life and efficiency hours of each turbine to a large extent. Diagrams were drawn to determine efficiency hours of each turbine based on rate and size of corrosion diameter, that have effect on defect. The experimental and simulation results were significantly consistent, and size of corrosion diameter was obtained by ultrasound waves that it is a new method in ultrasonic testing.

Defects in Turbine Impeller Blades with Non-destructive Testing: Modeling, Ultrasonic Waves, Defect Analysis

A Review of Ultrasonic Testing Applications in Spot Welding: Defect Evaluation in Experimental and Simulation Results

This paper investigates the impact of defects on similar sheets and dissimilar sheets used in the automotive industry. Spot welding is one of the types of resistance welding used in this experiment for sheet welding. The thickness of sheets welded by the spot welding method can be between 0.5 and 3 mm. In this paper, the simulation is performed by finite element method for non-destructive tests on spot welding. This study investigated the propagation of ultrasonic waves in two similar layers of stainless steel and galvanized stainless steel sheets and two dissimilar layers of stainless steel sheets and galvanized stainless steel sheets in different thicknesses. This test was performed by ultrasonic immersion method and the intensity and amplitude of the reaction of the resulting defect waves and its effect on the results were also investigated. Due to the performance of finite element method softwares, Comsol Multiphysics software because of its high accuracy used. It has been studied various factors and conditions including excitation frequency, boundary conditions, the most suitable position for the probr Fto stimulate the waves, focused or unfocused waves in the simulation, sensitivity analysis of mesh size and appropriate mesh size for simulation. In this paper, the joint of similar sheets and dissimilar sheets is investigated. For this performance, the average relative error that can meet the industrial requirement is mentioned. The results of the simulation with the results of the experimental test They were compared and investigated And with the amount of error tests, have acceptable results and it can be used with the error specified and can meet the needs of the automotive industry.

Numerical and Experimental Modeling of Spot Welding Defects by Ultrasonic Testing on Similar Sheets and Dissimilar Sheets

Defect of roller bearings shell may have many defects for rotary machines due to alternative connection forces and external impact loads, such as surface cracks fault results from corrosion or wear. Investigating the methods of detecting surface cracking defects for roller bearings shell is very useful for maintaining these machines. The new faults detection method was based on sent signals by amplitude and frequency by a multi-probe (FDDP) device due to influence of different frequency spectrum in order to detect surface cracking fault in the outer wall of the roller bearings shell. The finite element model was obtained for the shell of roller bearings by simulating the surface cracking defect in its outer wall and then by new method to use various probes for measure in the frequency domain of high detection fault cracking echoes. Differences in amplitude and signal received from the flawless bearing shell with surface cracking defects have been investigated and it used to detect the position of the surface cracking defect in the outer bearing wall. Experimental and simulation results indicated that the differences between the previous method and the new method for measuring the surface cracking defect in the outer wall of the roller bearing shell by using the new method of more probes with different frequencies (FDDP) simultaneously and without the time delay can be used to detect the location of the crack fault and its size more quickly and reliably. High and low frequencies are sensitive to the effects of ultrasonic waves, which do not react naturally at low frequencies such as speed, and low speeds cause structural vibration, but at high frequencies, these defects will be clearly visible and less vibration. Ultrasound is an optional method for non-destructive testing by which defective echoes are detected by using normal probe by ultrasonic immersion. Experimental and simulation results indicated that the study of all previous cases for surface cracking defects of shell has less efficient than the discovery of the new current method in which the detection of defect size was clearly shown for 5 different states.

Modeling and Effect of Ultrasonic Waves on Bearing Shells in Industry by Non-Destructive Testing

Automotive Fire Control by Designing and Launching a New Intelligent System: Experimental Results, Automotive Notification Design, New Design Comparison Chart

Esmaeil Mirmahdi

Papers

Numerical and Experimental Modeling of Spot Welding Defects by Ultrasonic Testing on Similar Sheets and Dissimilar Sheets

Analysis and Examination of Aluminum Sheets Suitable for Automotion Body: Ultrasonic Testing, Signal Processing, Simulation

Modeling and Effect of Ultrasonic Waves on Bearing Shells in Industry by Non-Destructive Testing

A Review of Ultrasonic Testing Applications in Spot Welding: Defect Evaluation in Experimental and Simulation Results

Automotive Fire Control by Designing and Launching a New Intelligent System: Experimental Results, Automotive Notification Design, New Design Comparison Chart