Pub Date : 2021-01-01DOI: 10.12989/SSS.2021.27.1.123
V. Sarfarazi, S. Abharian, A. Ghorbani
Experimental and discrete element methods were used to investigate the effects of both of the non-persistent joints and hole on the failure behaviour of rock pillars under uniaxial compressive test. Concrete samples with dimension of 150 mm × 150 mm × 50 mm were prepared. Within the specimen, two echelon non-persistent notches and one hole were provided. The hole was inserted at the middle of the specimen. two joints were distributed on the three diagonal planes. the angle of diagonal plane related to horizontal axis were 15°, 30° and 45°. The angle of joints related to diagonal plane were 30°, 45°, 60°. Totally, 9 different configuration systems were prepared. In these configurations, the length of joints was taken as 20 mm. diameter of hole was 20 mm. Similar to those for joints configuration systems in the experimental tests, 9 models with different echelon non-persistent joint were prepared in numerical model. The axial load was applied to the model by rate of 0.05 mm/min. the results show that the failure process was mostly governed by both of the non-persistent joint angle and diagonal plane angle. The compressive strengths of the specimens were related to the fracture pattern and failure mechanism of the discontinuities. It was shown that the shear behaviour of discontinuities is related to the number of the induced tensile cracks which are increased by increasing the joint angle. The strength of samples increases by increasing both of the joint angle and diagonal plane angle. The failure pattern and failure strength are similar in both methods i.e., the experimental testing and the numerical simulation methods.
{"title":"Physical test and PFC modelling of rock pillar failure containing two neighboring joints and one hole","authors":"V. Sarfarazi, S. Abharian, A. Ghorbani","doi":"10.12989/SSS.2021.27.1.123","DOIUrl":"https://doi.org/10.12989/SSS.2021.27.1.123","url":null,"abstract":"Experimental and discrete element methods were used to investigate the effects of both of the non-persistent joints and hole on the failure behaviour of rock pillars under uniaxial compressive test. Concrete samples with dimension of 150 mm × 150 mm × 50 mm were prepared. Within the specimen, two echelon non-persistent notches and one hole were provided. The hole was inserted at the middle of the specimen. two joints were distributed on the three diagonal planes. the angle of diagonal plane related to horizontal axis were 15°, 30° and 45°. The angle of joints related to diagonal plane were 30°, 45°, 60°. Totally, 9 different configuration systems were prepared. In these configurations, the length of joints was taken as 20 mm. diameter of hole was 20 mm. Similar to those for joints configuration systems in the experimental tests, 9 models with different echelon non-persistent joint were prepared in numerical model. The axial load was applied to the model by rate of 0.05 mm/min. the results show that the failure process was mostly governed by both of the non-persistent joint angle and diagonal plane angle. The compressive strengths of the specimens were related to the fracture pattern and failure mechanism of the discontinuities. It was shown that the shear behaviour of discontinuities is related to the number of the induced tensile cracks which are increased by increasing the joint angle. The strength of samples increases by increasing both of the joint angle and diagonal plane angle. The failure pattern and failure strength are similar in both methods i.e., the experimental testing and the numerical simulation methods.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66186765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.12989/SSS.2021.27.1.073
M. Ezzat
While in several publications the thermo-viscoelastic properties of solids have been documented, no attempt has been made to examine the action of coupled thermal and plasma wave in viscoelastic materials. In this paper, a new mathematical model for thermal and plasma transfer in an organic semiconductor was constructed with a time-fractional derivative of order
{"title":"A novel model of fractional thermal and plasma transfer within a non-metallic plate","authors":"M. Ezzat","doi":"10.12989/SSS.2021.27.1.073","DOIUrl":"https://doi.org/10.12989/SSS.2021.27.1.073","url":null,"abstract":"While in several publications the thermo-viscoelastic properties of solids have been documented, no attempt has been made to examine the action of coupled thermal and plasma wave in viscoelastic materials. In this paper, a new mathematical model for thermal and plasma transfer in an organic semiconductor was constructed with a time-fractional derivative of order","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66187171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.12989/SSS.2021.27.1.035
Orkan Özcan, Okan Özcan
An automated unmanned aerial vehicle (UAV) based multi-hazard performance assessment system was developed to respond to rapid performance evaluation and performance prediction needs for river crossing reinforced concrete (RC) bridges. In the developed system, firstly the seasonally acquired UAV measurements were used to obtain the three-dimensional (3D) digital elevation models (DEMs) of the river bed. In conjunction with the flood simulation, the hydraulic model was verified with the previous flood event which corresponded to Q50 and the scour depths after a probable flood (Q500) were predicted by HEC-RAS software. Afterward, the 3D finite element model (FEM) of the bridge was constituted automatically with the developed code considering the scoured piles. The flood loads were exerted on the modeled bridge with regard to the HEC-RAS flood inundation map and relevant water depth estimations around the bridge piers. For the seismic evaluation, nonlinear time history analyses (THA) were conducted by using several scaled earthquake acceleration records that were acting in both principal axes of the bridge simultaneously as compatible with the region seismicity. The Bogacay-II Bridge that was located in Antalya, Turkey was selected as the case study. In the analyses, as the scour depth increased, the lateral displacements and the pile internal forces were observed to increase while the pier column internal forces kept approximately constant. Thus, it was monitored that the seismic displacement and load demands migrated from pier columns to piles with increasing scour. Therefore, the applicability of the proposed system was verified using the case study bridge.
{"title":"Automated UAV based multi-hazard assessment system for bridges crossing seasonal rivers","authors":"Orkan Özcan, Okan Özcan","doi":"10.12989/SSS.2021.27.1.035","DOIUrl":"https://doi.org/10.12989/SSS.2021.27.1.035","url":null,"abstract":"An automated unmanned aerial vehicle (UAV) based multi-hazard performance assessment system was developed to respond to rapid performance evaluation and performance prediction needs for river crossing reinforced concrete (RC) bridges. In the developed system, firstly the seasonally acquired UAV measurements were used to obtain the three-dimensional (3D) digital elevation models (DEMs) of the river bed. In conjunction with the flood simulation, the hydraulic model was verified with the previous flood event which corresponded to Q50 and the scour depths after a probable flood (Q500) were predicted by HEC-RAS software. Afterward, the 3D finite element model (FEM) of the bridge was constituted automatically with the developed code considering the scoured piles. The flood loads were exerted on the modeled bridge with regard to the HEC-RAS flood inundation map and relevant water depth estimations around the bridge piers. For the seismic evaluation, nonlinear time history analyses (THA) were conducted by using several scaled earthquake acceleration records that were acting in both principal axes of the bridge simultaneously as compatible with the region seismicity. The Bogacay-II Bridge that was located in Antalya, Turkey was selected as the case study. In the analyses, as the scour depth increased, the lateral displacements and the pile internal forces were observed to increase while the pier column internal forces kept approximately constant. Thus, it was monitored that the seismic displacement and load demands migrated from pier columns to piles with increasing scour. Therefore, the applicability of the proposed system was verified using the case study bridge.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66187112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.12989/SSS.2021.27.1.101
Jian Zhang, Qu Chunxu, T. Yi, Hongnan Li
Concrete bridge decks may suffer local damage such as delamination, cracking, reinforcement corrosion and spalling during service. Visual inspection and nondestructive evaluation (NDE) technologies are extensively used for monitoring damage in bridge decks. This paper presents a damage detection method for decks of concrete girder bridges using the frequency obtained from an actively excited vehicle. First, the solution for the frequency of the deck with a concentrated mass is derived with Rayleigh's method, where the bridge deck is regarded as a slab supported on four sides, and the test vehicle is simplified as a concentrated mass. The validity of the proposed method that uses the frequency change to detect the local damage is verified. Then, the damage detection procedure for bridge decks is proposed, and the numerical analysis is performed on a typical concrete girder bridge to prove the validity of the method. Finally, the damage detection experiment for the plywood plate verifies the effectiveness of the proposed method. The results of this study provide an effective method for detecting damage in the decks of concrete girder bridges, which is time-saving and easier to implement.
{"title":"Damage detection for decks of concrete girder bridges using the frequency obtained from an actively excited vehicle","authors":"Jian Zhang, Qu Chunxu, T. Yi, Hongnan Li","doi":"10.12989/SSS.2021.27.1.101","DOIUrl":"https://doi.org/10.12989/SSS.2021.27.1.101","url":null,"abstract":"Concrete bridge decks may suffer local damage such as delamination, cracking, reinforcement corrosion and spalling during service. Visual inspection and nondestructive evaluation (NDE) technologies are extensively used for monitoring damage in bridge decks. This paper presents a damage detection method for decks of concrete girder bridges using the frequency obtained from an actively excited vehicle. First, the solution for the frequency of the deck with a concentrated mass is derived with Rayleigh's method, where the bridge deck is regarded as a slab supported on four sides, and the test vehicle is simplified as a concentrated mass. The validity of the proposed method that uses the frequency change to detect the local damage is verified. Then, the damage detection procedure for bridge decks is proposed, and the numerical analysis is performed on a typical concrete girder bridge to prove the validity of the method. Finally, the damage detection experiment for the plywood plate verifies the effectiveness of the proposed method. The results of this study provide an effective method for detecting damage in the decks of concrete girder bridges, which is time-saving and easier to implement.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66186926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.12989/SSS.2021.27.1.053
D. Kang, H. Kim, Myeongcheol Kang, Mun-Young Hwang, Lae-Hyong Kang, C. Joo
Gravel scattering, which occurs from snow-ice that develops on trains during winter, is a major cause of damage to train parts. An exothermic technology that uses copper wires to solve the problem of gravel scattering is ineffective on the snow-ice produced on the surface of the trains. Therefore, studies have been conducted to overcome the weaknesses of the conventional methods and to develop a paint-type surface exothermic technology that can be efficiently applied to complicated structures. However, multi-layered paint-type coatings can lead to problems such as a delamination or exfoliation of the layers when used for a long period of time within an environment undergoing variations in temperature. Therefore, this study assesses the long-term effects of temperature on multi-layered exothermic coating technology based on nano-solutions for an application of self-heating function on railway infrastructures. To do so, we developed an exothermic coating test specimen using the paint applied to train cars and commercial nano-solutions. To conduct an experiment on accelerated aging, the specimen was subjected to regular changes in the temperature within a thermal chamber. The results revealed that there is a nonlinear decline in the performance as the specimen is worn out in comparison to the exothermic performance achieved during the early stages. Further, it is possible to identify the structural causes of the decline in performance from the specimen applied thermal load by analyzing the morphology. However, it is possible to observe a high stability from noninvasive overheating or short-circuits based on the structural changes to the coating, which are observed during the assessment of the exothermic uniformity. Therefore, it can be concluded that a multi-layer exothermic coating, which can be effectively applied as an exothermic technology based on self-heating surfaces, can be applied for a long period to prevent disasters from freezing or snow-ice in trains during winter.
{"title":"Experimental investigation of long-term effects on temperature reliability of exothermic coating for smart railway structures with self-heating surfaces","authors":"D. Kang, H. Kim, Myeongcheol Kang, Mun-Young Hwang, Lae-Hyong Kang, C. Joo","doi":"10.12989/SSS.2021.27.1.053","DOIUrl":"https://doi.org/10.12989/SSS.2021.27.1.053","url":null,"abstract":"Gravel scattering, which occurs from snow-ice that develops on trains during winter, is a major cause of damage to train parts. An exothermic technology that uses copper wires to solve the problem of gravel scattering is ineffective on the snow-ice produced on the surface of the trains. Therefore, studies have been conducted to overcome the weaknesses of the conventional methods and to develop a paint-type surface exothermic technology that can be efficiently applied to complicated structures. However, multi-layered paint-type coatings can lead to problems such as a delamination or exfoliation of the layers when used for a long period of time within an environment undergoing variations in temperature. Therefore, this study assesses the long-term effects of temperature on multi-layered exothermic coating technology based on nano-solutions for an application of self-heating function on railway infrastructures. To do so, we developed an exothermic coating test specimen using the paint applied to train cars and commercial nano-solutions. To conduct an experiment on accelerated aging, the specimen was subjected to regular changes in the temperature within a thermal chamber. The results revealed that there is a nonlinear decline in the performance as the specimen is worn out in comparison to the exothermic performance achieved during the early stages. Further, it is possible to identify the structural causes of the decline in performance from the specimen applied thermal load by analyzing the morphology. However, it is possible to observe a high stability from noninvasive overheating or short-circuits based on the structural changes to the coating, which are observed during the assessment of the exothermic uniformity. Therefore, it can be concluded that a multi-layer exothermic coating, which can be effectively applied as an exothermic technology based on self-heating surfaces, can be applied for a long period to prevent disasters from freezing or snow-ice in trains during winter.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66187128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-01DOI: 10.12989/SSS.2020.26.5.559
H. Assilzadeh, Yangdong Cao, Sepideh Miraba, Shervin Rafiei, Aria Ghabussi, Fateme Bokaei, S. Baharom, P. Haramipour
One of the powerful data management tools is Building Information Modeling (BIM) which operates through obtaining, recalling, sharing, sorting and sorting data and supplying a digital environment of them. Employing SHM, a BIM in monitoring systems, would be an efficient method to address their data management problems and consequently optimize the economic aspects of buildings. The recording of SHM data is an effective way for engineers, facility managers and owners which make the BIM dynamic through the provision of updated information regarding the occurring state and health of different sections of the building. On the other hand, digital transformation is a continuous challenge in construction. In a cloud-based BIM platform, environmental and localization data are integrated which shape the Internet-of-Things (IoT) method. In order to improve work productivity, living comfort, and entertainment, the IoT has been growingly utilized in several products (such as wearables, smart homes). However, investigations confronting the integration of these two technologies (BIM and IoT) remain inadequate and solely focus upon the automatic transmission of sensor information to BIM models. Therefore, in this composition, the use of BIM based on SHM and IOT is reviewed and the economic application is considered.
{"title":"Economic application of structural health monitoring and internet of things in efficiency of building information modeling","authors":"H. Assilzadeh, Yangdong Cao, Sepideh Miraba, Shervin Rafiei, Aria Ghabussi, Fateme Bokaei, S. Baharom, P. Haramipour","doi":"10.12989/SSS.2020.26.5.559","DOIUrl":"https://doi.org/10.12989/SSS.2020.26.5.559","url":null,"abstract":"One of the powerful data management tools is Building Information Modeling (BIM) which operates through obtaining, recalling, sharing, sorting and sorting data and supplying a digital environment of them. Employing SHM, a BIM in monitoring systems, would be an efficient method to address their data management problems and consequently optimize the economic aspects of buildings. The recording of SHM data is an effective way for engineers, facility managers and owners which make the BIM dynamic through the provision of updated information regarding the occurring state and health of different sections of the building. On the other hand, digital transformation is a continuous challenge in construction. In a cloud-based BIM platform, environmental and localization data are integrated which shape the Internet-of-Things (IoT) method. In order to improve work productivity, living comfort, and entertainment, the IoT has been growingly utilized in several products (such as wearables, smart homes). However, investigations confronting the integration of these two technologies (BIM and IoT) remain inadequate and solely focus upon the automatic transmission of sensor information to BIM models. Therefore, in this composition, the use of BIM based on SHM and IOT is reviewed and the economic application is considered.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66186524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-01DOI: 10.12989/SSS.2020.26.4.403
Juncheng Gao, Mohammadreza Koopialipoor, D. J. Armaghani, Aria Ghabussi, S. Baharom, Armin Morasaei, A. Shariati, M. Khorami, Jian Zhou
In recent years, the use of Fiber Reinforced Polymers (FRPs) as one of the most common ways to increase the strength of concrete samples, has been introduced. Evaluation of the final strength of these specimens is performed with different experimental methods. In this research, due to the variety of models, the low accuracy and impact of different parameters, the use of new intelligence methods is considered. Therefore, using artificial intelligent-based models, a new solution for evaluating the bond strength of FRP is presented in this paper. 150 experimental samples were collected from previous studies, and then two new hybrid models of Imperialist Competitive Algorithm (ICA)-Artificial Neural Network (ANN) and Artificial Bee Colony (ABC)-ANN were developed. These models were evaluated using different performance indices and then, a comparison was made between the developed models. The results showed that the ICA-ANN model's ability to predict the bond strength of FRP is higher than the ABC-ANN model. Finally, to demonstrate the capabilities of this new model, a comparison was made between the five experimental models and the results were presented for all data. This comparison showed that the new model could offer better performance. It is concluded that the proposed hybrid models can be utilized in the field of this study as a suitable substitute for empirical models.
{"title":"Evaluating the bond strength of FRP in concrete samples using machine learning methods","authors":"Juncheng Gao, Mohammadreza Koopialipoor, D. J. Armaghani, Aria Ghabussi, S. Baharom, Armin Morasaei, A. Shariati, M. Khorami, Jian Zhou","doi":"10.12989/SSS.2020.26.4.403","DOIUrl":"https://doi.org/10.12989/SSS.2020.26.4.403","url":null,"abstract":"In recent years, the use of Fiber Reinforced Polymers (FRPs) as one of the most common ways to increase the strength of concrete samples, has been introduced. Evaluation of the final strength of these specimens is performed with different experimental methods. In this research, due to the variety of models, the low accuracy and impact of different parameters, the use of new intelligence methods is considered. Therefore, using artificial intelligent-based models, a new solution for evaluating the bond strength of FRP is presented in this paper. 150 experimental samples were collected from previous studies, and then two new hybrid models of Imperialist Competitive Algorithm (ICA)-Artificial Neural Network (ANN) and Artificial Bee Colony (ABC)-ANN were developed. These models were evaluated using different performance indices and then, a comparison was made between the developed models. The results showed that the ICA-ANN model's ability to predict the bond strength of FRP is higher than the ABC-ANN model. Finally, to demonstrate the capabilities of this new model, a comparison was made between the five experimental models and the results were presented for all data. This comparison showed that the new model could offer better performance. It is concluded that the proposed hybrid models can be utilized in the field of this study as a suitable substitute for empirical models.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66185510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.12989/SSS.2020.25.3.311
Jincheng Ding, Bin Huang, Hongwang Lv, Hongxia Wan
{"title":"Parametric study of SMA helical spring braces for the seismic resistance of a frame structure","authors":"Jincheng Ding, Bin Huang, Hongwang Lv, Hongxia Wan","doi":"10.12989/SSS.2020.25.3.311","DOIUrl":"https://doi.org/10.12989/SSS.2020.25.3.311","url":null,"abstract":"","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66184453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.12989/SSS.2020.25.1.001
Shahin Lale Arefi, A. Gholizad, S. M. Seyedpoor
The modal strain energy method is one of the efficient methods for detecting damage in the structures. Due to existing some limitations in real-world structures, sensors can only be located on a limited number of degrees of freedom (DOFs) of a structure. Therefore, the mode shape values in all DOFs of structures cannot be measured. In this paper, a modified modal strain energy based index (MMSEBI) is introduced to locate damaged elements of structures when a limited number of sensors are used. The proposed MMSEBI is based on the reconstruction of mode shapes using Improved Reduction System (IRS) method. Therefore, in the first step by employing IRS method, mode shapes in slave degrees of freedom are estimated by those of master degrees of freedom. In the second step, the proposed MMSEBI is used to located damage elements. In order to evaluate the efficiency of the proposed method, two numerical examples are considered under different damage patterns considering the measurement noise. Moreover, the universal threshold based on statistical hypothesis testing principles is applied to damage index values. The results show the effectiveness of the proposed MMSEBI for the structural damage localization when comparing with the available damage index named MESBI. The results demonstrate that the presented method can be used as a practical strategy for structural damage identification, especially when a limited number of sensors are installed on the structure. Finally, the combination of MMSEBI and IRS method can provide a reliable tool to identify the location of damage accurately.
{"title":"A modified index for damage detection of structures using improved reduction system method","authors":"Shahin Lale Arefi, A. Gholizad, S. M. Seyedpoor","doi":"10.12989/SSS.2020.25.1.001","DOIUrl":"https://doi.org/10.12989/SSS.2020.25.1.001","url":null,"abstract":"The modal strain energy method is one of the efficient methods for detecting damage in the structures. Due to existing some limitations in real-world structures, sensors can only be located on a limited number of degrees of freedom (DOFs) of a structure. Therefore, the mode shape values in all DOFs of structures cannot be measured. In this paper, a modified modal strain energy based index (MMSEBI) is introduced to locate damaged elements of structures when a limited number of sensors are used. The proposed MMSEBI is based on the reconstruction of mode shapes using Improved Reduction System (IRS) method. Therefore, in the first step by employing IRS method, mode shapes in slave degrees of freedom are estimated by those of master degrees of freedom. In the second step, the proposed MMSEBI is used to located damage elements. In order to evaluate the efficiency of the proposed method, two numerical examples are considered under different damage patterns considering the measurement noise. Moreover, the universal threshold based on statistical hypothesis testing principles is applied to damage index values. The results show the effectiveness of the proposed MMSEBI for the structural damage localization when comparing with the available damage index named MESBI. The results demonstrate that the presented method can be used as a practical strategy for structural damage identification, especially when a limited number of sensors are installed on the structure. Finally, the combination of MMSEBI and IRS method can provide a reliable tool to identify the location of damage accurately.","PeriodicalId":51155,"journal":{"name":"Smart Structures and Systems","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66184572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}