Active Infrared Thermography for Defect Detection of Polyethylene Pipes

2014 ◽  
Vol 1044-1045 ◽  
pp. 700-703
Author(s):  
Zhi Bin Zhu ◽  
Xu Qiu ◽  
Shun Cong Zhong ◽  
Xi Bin Fu ◽  
Xiao Xiang Yang
Keyword(s):  
Finite Element ◽  
Infrared Thermography ◽  
Defect Detection ◽  
Infrared Imaging ◽  
Experimental System ◽  
Element Model ◽  
Electrical Heating ◽  
Thermal Excitation ◽  
Flux Boundary Condition ◽  
Active Infrared Thermography

We present defect detection of polyethylene (PE) pipes by using active infrared thermography technique. A finite element model was built to mimic the transient heat transfer in PE pipes, in which constant heat flux boundary condition was applied to the inner surface of the PE pipes. Various defects with different diameters and depths were simulated in PE pipes and they would affect the thermal distributions from which the relation between thermal images and defect sizes and locations would be established. An electrical heating bar, as the novel thermal excitation source, was employed in active infrared thermography experimental system. The finite element simulation results are well agreed with the one obtained from the infrared imaging experiments and it demonstrated that finite element numerical method can be an effective method to analyze infrared imaging. Furthermore, defects in heat fusion joints of PE pipes were fabricated and detected by the developed active infrared thermography. The experiment showed that active infrared thermography based on an electrical heating bar could provide a novel tool for nondestructive evaluation of PE pipes.

Thermal Response for a Reinforced Concrete Slab Analyzed with Active Infrared Thermography and Comsol Multiphysics

2015 ◽  
Vol 760 ◽  
pp. 627-632
Author(s):  
Razvan Gabriel Dragan ◽  
Ileana Constanta Rosca ◽  
Diana Cazangiu ◽  
Alexandru Stefan Leonte
Keyword(s):  
Reinforced Concrete ◽  
Infrared Thermography ◽  
Concrete Slab ◽  
Infrared Camera ◽  
Heat Transfer Process ◽  
Electrical Heating ◽  
Comsol Multiphysics ◽  
Reinforced Concrete Slab ◽  
Thermal Distribution ◽  
Active Infrared Thermography

This paper presents a non-destructive technique (NDT) using active infrared thermography and FEM analyses with Comsol Multiphysics software applied for thermal distribution detection through reinforced concrete. For this work a reinforced concrete slab was created having a parallelepiped shape, the length and the width of 400 mm and the thickness of 50 mm. The concrete slab was reinforced using a rebar mesh of 18 mm diameter. The experimental installation consisted of an electrical heating source and a steel frame for fixing the slab and for the thermal distribution analyses an infrared camera was used. The same type of material and conditions like in the laboratory was used for the FEM analyses in Comsol Multiphysiscs to compare with the experimental part. A concrete slab without steel was used to determine the difference between the simple concrete and reinforced concrete in the heat transfer process.

Thermomechanical Modelling and Experimental Testing of a Shape Memory Alloy Hybrid Composite Plate

2008 ◽  
Vol 59 ◽  
pp. 41-46 ◽  
Author(s):  
Federica Daghia ◽  
Gabriella Faiella ◽  
Vincenza Antonucci ◽  
Michele Giordano
Keyword(s):  
Finite Element ◽  
Shape Memory Alloy ◽  
Finite Element Model ◽  
Shape Memory ◽  
Functional Properties ◽  
Hybrid Composite ◽  
Experimental Testing ◽  
Element Model ◽  
Electrical Heating ◽  
Simultaneous Generation

Shape memory alloys (SMA) exhibit functional properties associated with the shape memory effect, responsible of the SMA shape recovery after a cycle of deforming-heating and of a simultaneous generation of mechanical work. Composite systems incorporating SMA wires have the ability to actively change shape and other structural characteristics. The functional properties of such adaptive composites are related to the martensitic transformation in the SMA elements and to the constraining behaviour that the composite matrix has on the SMA wires. In this work the behaviour of a shape memory alloy hybrid composite (SMAHC) is numerically and experimentally investigated. A plate was fabricated using prestrained SMA wires embedded in an epoxy resin pre preg glass fibres composite system. Upon calorimetric and mechanical material characterization, a finite element model was used in order to predict the structural behaviour of the SMAHC. In the experimental tests, the plate was clamped at one side and actuated via electrical heating. Temperature and displacement data were collected and compared with the prediction of the finite element model. The results show that the model is able to capture the shape change in the actuation region, although a thorough description of the SMAHC behaviour requires further modelling work, including the simulation of the SMA loading history during composite manufacturing.

FEM Modelling and Experimental Verification of a Rotor System With a Open Crack

2009 ◽  
Author(s):  
Tsuyoshi Inoue ◽  
Nobuhiro Nagata ◽  
Yukio Ishida
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Natural Frequencies ◽  
Experimental System ◽  
Element Model ◽  
Rotor System ◽  
Open Crack ◽  
Rotating Shaft ◽  
Risk Condition ◽  
Resonance Curves

Continuous operation of rotating machinery with a rotor crack is a risk condition since the rotor crack grows rapidly and may fail causing a catastrophic accident. This paper develops the finite element model of the rotating shaft with an open crack. The natural frequencies and the resonance curves of such a rotor system with an open crack is investigated, and the concise and accurate modeling of the open crack element is discussed. The natural frequencies and the resonance curves of the experimental system are measured for various positions and depths of the open crack. By comparing both the theoretical and experimental results, the accuracy of the developed simple finite element model of the rotating shaft with an open crack is clarified.

Modal Analysis of a Suspension Assembly

1994 ◽  
Vol 116 (3) ◽  
pp. 377-386 ◽  
Author(s):  
C. J. Wilson ◽  
D. B. Bogy
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Experimental System ◽  
Element Model ◽  
Modal Parameters ◽  
Geometrical Features ◽  
Analysis System ◽  
P Type ◽  
Innovative Techniques ◽  
The Finite Element Model

The dynamic characteristics of a suspension assembly are examined using new numerical and experimental techniques. The p-type finite element method is used to construct a numerical model of the suspension. There are significant advantages in using this approach to analyze these types of structures. The model is verified by an experimental modal analysis system, which has been shown to be effective in the study of small structures. The modelled modal parameters agree within 4.5 percent with the experimental results for 14 modes. Since the experimental system uses an electromagnetic exciter, a ferromagnetic target must be attached to the nonferrous suspension so that it can be excited. Innovative techniques are investigated to improve the attachment of this ferromagnetic target. Furthermore, the finite element model is utilized to evaluate the sensitivity of the modal parameters of the suspension to changes in its geometrical features.

Strength Analysis and Structure Optimization of Constant Volume Combustion Bomb

2011 ◽  
Vol 233-235 ◽  
pp. 821-826 ◽  
Author(s):  
Xiao Fei Tian ◽  
Hong Guang Zhang ◽  
Xiao Lei Bai
Keyword(s):  
Finite Element ◽  
Structure Optimization ◽  
Experimental System ◽  
Basic Research ◽  
Element Model ◽  
Constant Volume ◽  
Strength Analysis ◽  
Solid Model ◽  
Ansys Software ◽  
Constant Volume Combustion

Constant Volume Combustion Bomb (CVCB) is a useful experimental system in the internal combustion basic research. A new structure of CVCB was designed in this paper. Its solid model and finite element model were built through Pro-Engineer and ANSYS software. Then the strength was calculated and the structure was optimized to get the smallest volume with ANSYS. According to the optimization results, the volume decreased 50%.

Residual Stress Distribution in Hard-Facing of Pressure Relief Valve Seat

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Li Ai ◽  
Xinhai Yu ◽  
Wenchun Jiang ◽  
Wanchuck Woo ◽  
Xiaofeng Ze ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Infrared Imaging ◽  
Element Model ◽  
Pressure Relief Valve ◽  
Stress Distributions ◽  
Relief Valve ◽  
Pressure Relief

In this study, for the hard-facing of spring-loaded pressure relief valve seats, the residual stress distributions after the tungsten inert gas welding, (TIG) postwelded heat treatment and subsequent surface turning were investigated. The heat input parameters of welding were calibrated using an infrared imaging and thermocouples. The residual stress distributions were computed using three-dimensional finite element model. The neutron diffraction approach was employed to verify the finite element calculation. It is found that, the surface temperature during hard-facing welding shows a double ellipsoidal shape with the highest value of around 1570 °C. The high residual stress zones are located exactly under the welded joint except a slight deviation in the hoop direction. The magnitudes of tensile residual stresses in the three directions increase with their corresponding locations from the root of the joint into the base metal. The residual stresses in all of the three directions decrease significantly after the heat treatment. After surface turning, the residual stresses are tensile except for those close to the inner surface that are compressive in axial and radial directions.

scholarly journals Performance of Fitness Functions Based on Natural Frequencies in Defect Detection Using the Standard PSO-FEM Approach

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Xiao-Lin Li ◽  
Roger Serra ◽  
Julien Olivier
Keyword(s):  
Finite Element ◽  
Defect Detection ◽  
Natural Frequencies ◽  
Fitness Function ◽  
Critical Factor ◽  
Element Model ◽  
Pso Algorithm ◽  
Population Diversity ◽  
Fitness Functions ◽  
Single Defect

Structural defect detection based on finite element model (FEM) updating is an optimization problem by minimizing the discrepancy of responses between model and measurement. Researchers have introduced many methods to perform the FEM updating for defect detection of the structures. A popular approach is to adopt the particle swarm optimization (PSO) algorithm. In this process, the fitness function is a critical factor in the success of the PSO-FEM approach. Our objective is to compare the performances of four fitness functions based on natural frequencies using the standard PSO-FEM approach for defect detection. In this paper, the definition of the standard PSO algorithm is first presented. After constructing the finite element benchmark model of the beam structure, four commonly used fitness functions based on natural frequencies are outlined. Their performance in defect detection of beam structures will be evaluated using the standard PSO-FEM approach. Finally, in the numerical simulations, the population diversity, success rate, mean iterations, and CPU time of the four fitness functions for the algorithm are calculated. The simulation results comprehensively evaluate their performances for single defect and multidefect scenario, and the effectiveness and superiority of the fitness function S 4 will be demonstrated.

The Experimental Research on Piezoelectric Vibration Control for the Simplified Autobody Beam Structure

2013 ◽  
Vol 816-817 ◽  
pp. 353-357
Author(s):  
Chuan Liang Shen ◽  
Da Xue Wang ◽  
Ye Han
Keyword(s):  
Finite Element ◽  
Vibration Control ◽  
Active Vibration Control ◽  
Experimental System ◽  
Element Model ◽  
Control Analysis ◽  
Beam Structure ◽  
Element Analysis ◽  
Active Vibration ◽  
Piezoelectric Vibration

The numerical simulation and experimental method are adopted to analyze the piezoelectric vibration control of the simplified autobody beam structure. The autobody beam structure is simplified as a beam fixed at both ends. The finite element model of beam structure with piezoelectric patches is established. The static analysis and modal analysis is conducted by the piezoelectric analysis of the finite element analysis software. The proportional and proportional-derivative control methods are studied in the piezoelectric active vibration control analysis for the simplified beam structure. The experimental system is established to obtain the vibration control effectiveness of the beam structure. The experimental results show that the type of two ends patching beam has more effective vibration control ability than the central patched beam.

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