The Experts below are selected from a list of 6714 Experts worldwide ranked by ideXlab platform
Gangbing Song - One of the best experts on this subject based on the ideXlab platform.
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smart washer a piezoceramic based transducer to monitor looseness of Bolted Connection
Smart Materials and Structures, 2017Co-Authors: Linsheng Huo, Gangbing Song, Qingzhao Kong, Dongdong ChenAbstract:The safety of a Bolted Connection, as one of the most common ways of making two or more parts/components work together in engineering structures, is very important in order to ensure the health of the whole structure. However, bolt loosening or pre-load degradation may induce the failure of the bolt Connection, threatening the normal operation of the system's structure. As a result, it would be beneficial if the health condition of the bolt Connection could be monitored in real time. In this paper, a 'smart washer', fabricated by embedding a piezoceramic patch into two pre-machined flat metal rings, was invented and then introduced as a transducer to detect the looseness of a Bolted Connection. A simple specimen, which consists of two steel plates connected by a nut, a bolt and two smart washers, was fabricated as the test object to study the performance of the 'smart washers' (SWs). For the specimen, a smart washer was used as an actuator to generate a stress wave, and the other one was used as a sensor to detect the propagated wave that traveled through the interface of the Bolted Connection. A time reversal method was employed to quantify the energy of the stress wave propagating between the two washers, and thus it was possible to build a relationship between the extent of any pre-loaded degradation of the bolt Connection and the response signal of the stress wave traveling between the two washers. In addition, a normalized bolt looseness index was proposed for evaluating the looseness of a bolt Connection based on wavelet energy analysis.
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Smart washer—a piezoceramic-based transducer to monitor looseness of Bolted Connection
Smart Materials and Structures, 2017Co-Authors: Linsheng Huo, Qingzhao Kong, Dongdong Chen, Gangbing SongAbstract:The safety of a Bolted Connection, as one of the most common ways of making two or more parts/components work together in engineering structures, is very important in order to ensure the health of the whole structure. However, bolt loosening or pre-load degradation may induce the failure of the bolt Connection, threatening the normal operation of the system's structure. As a result, it would be beneficial if the health condition of the bolt Connection could be monitored in real time. In this paper, a 'smart washer', fabricated by embedding a piezoceramic patch into two pre-machined flat metal rings, was invented and then introduced as a transducer to detect the looseness of a Bolted Connection. A simple specimen, which consists of two steel plates connected by a nut, a bolt and two smart washers, was fabricated as the test object to study the performance of the 'smart washers' (SWs). For the specimen, a smart washer was used as an actuator to generate a stress wave, and the other one was used as a sensor to detect the propagated wave that traveled through the interface of the Bolted Connection. A time reversal method was employed to quantify the energy of the stress wave propagating between the two washers, and thus it was possible to build a relationship between the extent of any pre-loaded degradation of the bolt Connection and the response signal of the stress wave traveling between the two washers. In addition, a normalized bolt looseness index was proposed for evaluating the looseness of a bolt Connection based on wavelet energy analysis.
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real time bolt preload monitoring using piezoceramic transducers and time reversal technique a numerical study with experimental verification
Smart Materials and Structures, 2016Co-Authors: Seyed Mohammad Parvasi, Qingzhao Kong, Reza Mousavi, Gangbing SongAbstract:Bolted joints are ubiquitous structural elements, and form critical Connections in mechanical and civil structures. As such, loosened Bolted joints may lead to catastrophic failures of these structures, thus inspiring a growing interest in monitoring of Bolted joints. A novel energy based wave method is proposed in this study to monitor the axial load of Bolted joint Connections. In this method, the time reversal technique was used to focus the energy of a piezoelectric (PZT)-generated ultrasound wave from one side of the interface to be measured as a signal peak by another PZT transducer on the other side of the interface. A tightness index (TI) was defined and used to correlate the peak amplitude to the bolt axial load. The TI bypasses the need for more complex signal processing required in other energy-based methods. A coupled, electro-mechanical analysis with elasto-plastic finite element method was used to simulate and analyze the PZT based ultrasonic wave propagation through the interface of two steel plates connected by a single nut and bolt Connection. Numerical results, backed by experimental results from testing on a Bolted Connection between two steel plates, revealed that the peak amplitude of the focused signal increases as the bolt preload (torque level) increases due to the enlarging true contact area of the steel plates. The amplitude of the focused peak saturates and the TI reaches unity as the bolt axial load reaches a threshold value. These conditions are associated with the maximum possible true contact area between the surfaces of the Bolted Connection.
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proof of concept study of monitoring bolt Connection status using a piezoelectric based active sensing method
Smart Materials and Structures, 2013Co-Authors: Tao Wang, Gangbing Song, Zhigang Wang, Yourong LiAbstract:Aimed at monitoring bolt Connection status and detecting bolt loosening, a piezoceramic based active sensing method is developed in this article. Two piezoceramic patches are bonded to the two different parts of a Bolted Connection. In the active sensing approach, one piezoceramic patch is used as an actuator to generate an ultrasonic wave, and the other one is used to detect the wave that propagates through the Bolted Connection. The received energy depends on the interface fastening pressure which is determined by the bolt torque. By analyzing the received energy, the status of bolt Connection and bolt loosening can be detected. To study the effectiveness of the proposed method, an experiment apparatus is set up, and the experimental results show that the wave energy propagated across the interface is proportional to the torque level that is used to pretension the bolt. This experimental study demonstrates the potential of the piezoceramic based active sensing method for the monitoring of bolt loosening status.
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Review of Bolted Connection Monitoring
International Journal of Distributed Sensor Networks, 2013Co-Authors: Tao Wang, Gangbing Song, Shaopeng Liu, Xiao HanAbstract:This paper reviews the research of monitoring technologies for Bolted structural Connections. The acoustoelastic effect based method, the piezoelectric active sensing method, and the piezoelectric impedance method are the three commonly used to monitor Bolted Connections. The basic principle and the applications of these three methods are discussed in detail in this paper. In addition, this paper presents a comparison of these methods and discusses their suitability for in situ or real-time bolt Connection monitoring.
Qingzhao Kong - One of the best experts on this subject based on the ideXlab platform.
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smart washer a piezoceramic based transducer to monitor looseness of Bolted Connection
Smart Materials and Structures, 2017Co-Authors: Linsheng Huo, Gangbing Song, Qingzhao Kong, Dongdong ChenAbstract:The safety of a Bolted Connection, as one of the most common ways of making two or more parts/components work together in engineering structures, is very important in order to ensure the health of the whole structure. However, bolt loosening or pre-load degradation may induce the failure of the bolt Connection, threatening the normal operation of the system's structure. As a result, it would be beneficial if the health condition of the bolt Connection could be monitored in real time. In this paper, a 'smart washer', fabricated by embedding a piezoceramic patch into two pre-machined flat metal rings, was invented and then introduced as a transducer to detect the looseness of a Bolted Connection. A simple specimen, which consists of two steel plates connected by a nut, a bolt and two smart washers, was fabricated as the test object to study the performance of the 'smart washers' (SWs). For the specimen, a smart washer was used as an actuator to generate a stress wave, and the other one was used as a sensor to detect the propagated wave that traveled through the interface of the Bolted Connection. A time reversal method was employed to quantify the energy of the stress wave propagating between the two washers, and thus it was possible to build a relationship between the extent of any pre-loaded degradation of the bolt Connection and the response signal of the stress wave traveling between the two washers. In addition, a normalized bolt looseness index was proposed for evaluating the looseness of a bolt Connection based on wavelet energy analysis.
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Smart washer—a piezoceramic-based transducer to monitor looseness of Bolted Connection
Smart Materials and Structures, 2017Co-Authors: Linsheng Huo, Qingzhao Kong, Dongdong Chen, Gangbing SongAbstract:The safety of a Bolted Connection, as one of the most common ways of making two or more parts/components work together in engineering structures, is very important in order to ensure the health of the whole structure. However, bolt loosening or pre-load degradation may induce the failure of the bolt Connection, threatening the normal operation of the system's structure. As a result, it would be beneficial if the health condition of the bolt Connection could be monitored in real time. In this paper, a 'smart washer', fabricated by embedding a piezoceramic patch into two pre-machined flat metal rings, was invented and then introduced as a transducer to detect the looseness of a Bolted Connection. A simple specimen, which consists of two steel plates connected by a nut, a bolt and two smart washers, was fabricated as the test object to study the performance of the 'smart washers' (SWs). For the specimen, a smart washer was used as an actuator to generate a stress wave, and the other one was used as a sensor to detect the propagated wave that traveled through the interface of the Bolted Connection. A time reversal method was employed to quantify the energy of the stress wave propagating between the two washers, and thus it was possible to build a relationship between the extent of any pre-loaded degradation of the bolt Connection and the response signal of the stress wave traveling between the two washers. In addition, a normalized bolt looseness index was proposed for evaluating the looseness of a bolt Connection based on wavelet energy analysis.
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real time bolt preload monitoring using piezoceramic transducers and time reversal technique a numerical study with experimental verification
Smart Materials and Structures, 2016Co-Authors: Seyed Mohammad Parvasi, Qingzhao Kong, Reza Mousavi, Gangbing SongAbstract:Bolted joints are ubiquitous structural elements, and form critical Connections in mechanical and civil structures. As such, loosened Bolted joints may lead to catastrophic failures of these structures, thus inspiring a growing interest in monitoring of Bolted joints. A novel energy based wave method is proposed in this study to monitor the axial load of Bolted joint Connections. In this method, the time reversal technique was used to focus the energy of a piezoelectric (PZT)-generated ultrasound wave from one side of the interface to be measured as a signal peak by another PZT transducer on the other side of the interface. A tightness index (TI) was defined and used to correlate the peak amplitude to the bolt axial load. The TI bypasses the need for more complex signal processing required in other energy-based methods. A coupled, electro-mechanical analysis with elasto-plastic finite element method was used to simulate and analyze the PZT based ultrasonic wave propagation through the interface of two steel plates connected by a single nut and bolt Connection. Numerical results, backed by experimental results from testing on a Bolted Connection between two steel plates, revealed that the peak amplitude of the focused signal increases as the bolt preload (torque level) increases due to the enlarging true contact area of the steel plates. The amplitude of the focused peak saturates and the TI reaches unity as the bolt axial load reaches a threshold value. These conditions are associated with the maximum possible true contact area between the surfaces of the Bolted Connection.
Linsheng Huo - One of the best experts on this subject based on the ideXlab platform.
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smart washer a piezoceramic based transducer to monitor looseness of Bolted Connection
Smart Materials and Structures, 2017Co-Authors: Linsheng Huo, Gangbing Song, Qingzhao Kong, Dongdong ChenAbstract:The safety of a Bolted Connection, as one of the most common ways of making two or more parts/components work together in engineering structures, is very important in order to ensure the health of the whole structure. However, bolt loosening or pre-load degradation may induce the failure of the bolt Connection, threatening the normal operation of the system's structure. As a result, it would be beneficial if the health condition of the bolt Connection could be monitored in real time. In this paper, a 'smart washer', fabricated by embedding a piezoceramic patch into two pre-machined flat metal rings, was invented and then introduced as a transducer to detect the looseness of a Bolted Connection. A simple specimen, which consists of two steel plates connected by a nut, a bolt and two smart washers, was fabricated as the test object to study the performance of the 'smart washers' (SWs). For the specimen, a smart washer was used as an actuator to generate a stress wave, and the other one was used as a sensor to detect the propagated wave that traveled through the interface of the Bolted Connection. A time reversal method was employed to quantify the energy of the stress wave propagating between the two washers, and thus it was possible to build a relationship between the extent of any pre-loaded degradation of the bolt Connection and the response signal of the stress wave traveling between the two washers. In addition, a normalized bolt looseness index was proposed for evaluating the looseness of a bolt Connection based on wavelet energy analysis.
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Smart washer—a piezoceramic-based transducer to monitor looseness of Bolted Connection
Smart Materials and Structures, 2017Co-Authors: Linsheng Huo, Qingzhao Kong, Dongdong Chen, Gangbing SongAbstract:The safety of a Bolted Connection, as one of the most common ways of making two or more parts/components work together in engineering structures, is very important in order to ensure the health of the whole structure. However, bolt loosening or pre-load degradation may induce the failure of the bolt Connection, threatening the normal operation of the system's structure. As a result, it would be beneficial if the health condition of the bolt Connection could be monitored in real time. In this paper, a 'smart washer', fabricated by embedding a piezoceramic patch into two pre-machined flat metal rings, was invented and then introduced as a transducer to detect the looseness of a Bolted Connection. A simple specimen, which consists of two steel plates connected by a nut, a bolt and two smart washers, was fabricated as the test object to study the performance of the 'smart washers' (SWs). For the specimen, a smart washer was used as an actuator to generate a stress wave, and the other one was used as a sensor to detect the propagated wave that traveled through the interface of the Bolted Connection. A time reversal method was employed to quantify the energy of the stress wave propagating between the two washers, and thus it was possible to build a relationship between the extent of any pre-loaded degradation of the bolt Connection and the response signal of the stress wave traveling between the two washers. In addition, a normalized bolt looseness index was proposed for evaluating the looseness of a bolt Connection based on wavelet energy analysis.
Dongdong Chen - One of the best experts on this subject based on the ideXlab platform.
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smart washer a piezoceramic based transducer to monitor looseness of Bolted Connection
Smart Materials and Structures, 2017Co-Authors: Linsheng Huo, Gangbing Song, Qingzhao Kong, Dongdong ChenAbstract:The safety of a Bolted Connection, as one of the most common ways of making two or more parts/components work together in engineering structures, is very important in order to ensure the health of the whole structure. However, bolt loosening or pre-load degradation may induce the failure of the bolt Connection, threatening the normal operation of the system's structure. As a result, it would be beneficial if the health condition of the bolt Connection could be monitored in real time. In this paper, a 'smart washer', fabricated by embedding a piezoceramic patch into two pre-machined flat metal rings, was invented and then introduced as a transducer to detect the looseness of a Bolted Connection. A simple specimen, which consists of two steel plates connected by a nut, a bolt and two smart washers, was fabricated as the test object to study the performance of the 'smart washers' (SWs). For the specimen, a smart washer was used as an actuator to generate a stress wave, and the other one was used as a sensor to detect the propagated wave that traveled through the interface of the Bolted Connection. A time reversal method was employed to quantify the energy of the stress wave propagating between the two washers, and thus it was possible to build a relationship between the extent of any pre-loaded degradation of the bolt Connection and the response signal of the stress wave traveling between the two washers. In addition, a normalized bolt looseness index was proposed for evaluating the looseness of a bolt Connection based on wavelet energy analysis.
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Smart washer—a piezoceramic-based transducer to monitor looseness of Bolted Connection
Smart Materials and Structures, 2017Co-Authors: Linsheng Huo, Qingzhao Kong, Dongdong Chen, Gangbing SongAbstract:The safety of a Bolted Connection, as one of the most common ways of making two or more parts/components work together in engineering structures, is very important in order to ensure the health of the whole structure. However, bolt loosening or pre-load degradation may induce the failure of the bolt Connection, threatening the normal operation of the system's structure. As a result, it would be beneficial if the health condition of the bolt Connection could be monitored in real time. In this paper, a 'smart washer', fabricated by embedding a piezoceramic patch into two pre-machined flat metal rings, was invented and then introduced as a transducer to detect the looseness of a Bolted Connection. A simple specimen, which consists of two steel plates connected by a nut, a bolt and two smart washers, was fabricated as the test object to study the performance of the 'smart washers' (SWs). For the specimen, a smart washer was used as an actuator to generate a stress wave, and the other one was used as a sensor to detect the propagated wave that traveled through the interface of the Bolted Connection. A time reversal method was employed to quantify the energy of the stress wave propagating between the two washers, and thus it was possible to build a relationship between the extent of any pre-loaded degradation of the bolt Connection and the response signal of the stress wave traveling between the two washers. In addition, a normalized bolt looseness index was proposed for evaluating the looseness of a bolt Connection based on wavelet energy analysis.
Tae Soo Kim - One of the best experts on this subject based on the ideXlab platform.
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Development on ultimate strength equation of ferritic stainless steel (STS430) two-Bolted Connection:
Advances in Structural Engineering, 2019Co-Authors: Tae Soo Kim, Bokyung Hwang, Young-chul LimAbstract:This article presents the experimental and numerical results of cold-formed ferritic stainless steel (STS430) Bolted Connection with two bolts. Single-shear Bolted Connections with varying end dist...
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block shear strength of cold formed austenitic stainless steel 304 type welded Connection with base metal fracture
Thin-walled Structures, 2019Co-Authors: Hoochang Lee, Bokyung Hwang, Wonjik Yang, Tae Soo KimAbstract:Abstract In this paper, the block shear fracture behavior of base metal in austenitic stainless steel (STS304, corresponds to ASTM 304 type) fillet-welded Connection has been investigated through experimental and numerical methods. Even though the block shear fracture strength of welded Connection thanks to stress triaxiality effect differs from those of Bolted Connection under monotonic tension, block shear strength equations of welded Connection with base metal fracture in the design codes are identical to those of Bolted Connection. Main variables are weld method (TIG and Arc welding) and weld length (transverse and longitudinal to the direction of loading). It is found from study results that welding method did not affect the strength of welded Connection. Block shear strengths by current codes (KBC2016, AISC2016 and EC3 1–3) and other researchers’ proposed equations were compared with those of experimental results and finite element analysis results. Finite element analysis (FEA) model was developed based on previously test data. Also, parametric study for investigating the weld length effect on strength has been performed with the developed finite element analysis procedures. Consequently, condition of weld length and end distance perpendicular to the direction of applied force for fracture mode transition boundary from tensile fracture to block shear fracture in welded Connection was investigated. In addition, block shear strength equation with modified tensile stress and shear stress factors of base metal fracture in austenitic stainless steel (STS304) welded Connection is suggested considering stress triaxiality.
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Strength of channel Bolted Connection with austenitic stainless steel (304 type)
International Journal of Steel Structures, 2015Co-Authors: Tae Soo Kim, Minseong Kim, Taejun ChoAbstract:Stainless steel has been widely utilized as structural materials of building due to significant characteristics in its superior corrosion resistance, durability, aesthetic appeal etc. Recently, experimental and numerical studies of structural behaviors and curling (out-of-plane deformation) influence for single shear Bolted Connection fabricated with thin-walled plane plates have been performed by Kim T.S. In this paper, finite element analysis (FEA) has been conducted based on the existing test result of channel Bolted Connections in austenitic stainless steel. The validation of numerical approach was verified to predict the structural behaviors of Bolted Connections such as fracture mode, ultimate strength and curling occurrence. Curling also occurred in the channel Bolted Connections with a long end distance like Bolted Connections assembled with plane plates. The curling reduced the ultimate strength and ultimate strength reduction caused by curling has been estimated quantitatively through the strength comparison of analysis results of FEA models with free edge and restrained curling. Additional parametric analysis for FEA models with extended variables has been performed. Therefore, the ultimate strengths were compared with current design strengths and modified strength formulae for channel Bolted Connections considering curling effect were proposed.
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a parametric study on ultimate strength of single shear Bolted Connections with curling
Thin-walled Structures, 2008Co-Authors: Tae Soo Kim, Hitoshi Kuwamura, T J ChoAbstract:Recommended procedures of finite element modeling for predicting the structural behaviors of single shear Bolted Connections in cold-formed austenitic stainless steel are presented in this paper. It was shown that predictions by FE analysis method were in a good correspondence with test results for ultimate behaviors such as failure mode, ultimate strength and out-of-plane curling. A parametric study on four-Bolted Connections with extended variables; plate thickness, end distance and edge distance is performed in order to consider the influence of curling on ultimate strength for practical design and ultimate strengths obtained from FE analysis results are also compared with those calculated by current design standards and recently modified equations by Kuwamura. It is found that Kuwamura's equations, which are specified by SSBA design manual are more valid for predicting ultimate strength of Bolted Connection without curling compared to other design specifications, while for specimens curled in FE analysis, Kuwamura's equations overestimated the ultimate strength due to strength reduction caused by curling and current other design standards showed a tendency to underestimate the ultimate strength of block shear fracture regardless of curling occurrence. Consequently, revised design formula for considering the effect of curling on Bolted Connection is proposed in this paper using correlations between strength reduction ratio and plate thickness. Furthermore, the validation of proposed design equations in predicting the ultimate strength is verified through comparisons with existing test results and additional FE analysis results.