Toru Takeuchi - Academia.edu (original) (raw)

Papers by Toru Takeuchi

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, Jul 1, 2023

In 2011, many roof bearings in large span facilities were damaged severely by the Pacific coast o... more In 2011, many roof bearings in large span facilities were damaged severely by the Pacific coast of Tohoku earthquake. Some of them were designed as slide bearings to release the thrust caused by the weight of roof. In ball-jointed system truss roof, bearings are subjected to horizontal movement and rotation since the roof structure has insufficient bending stiffness. In this study, we conducted the cyclic loading tests on conventional roof bearings and analyzed the observed behavior. In addition, we derived functions which express horizontal force in relation to horizontal displacement and rotation and verified by comparing with the test results.

IEEE Journal of Solid-state Circuits, Mar 24, 2005

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, Dec 1, 2022

This paper investigated the dynamic response characteristic with focus on damped slit configurati... more This paper investigated the dynamic response characteristic with focus on damped slit configuration of damped braced tube systems with oil dampers. According to the results, 1) damped braced tube system has over 10% 1st to 3rd damping ratio, 2) while the displacement and acceleration responses are simultaneously reduced up to maximized 1st mode damping ratio, the acceleration reduction effect may be getting worse after the peak, 3) while uniform damper distribution contributes to better damping performance, centralized damper distribution contributes to better period reduction.

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, 2005

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, Nov 1, 2022

While BRBs using laminated timber as a restrainer have been widely studied, timber restrainers ha... more While BRBs using laminated timber as a restrainer have been widely studied, timber restrainers have lower stiffness than steel restrainers with higher risk of fragile crack failure, it is necessary to consider the safety factor of global buckling, global stability of restrainer ends and local bulging failure at restrainer. In this study, a wide range of mock-up loading tests on BRBs with timber restrainer were carried out with different core-to-restraint compositions, in-plane and out-of-plane clearances, with and without core additional steel plates, and with different boundary conditions. Their exhibited failure modes are carefully studied and evaluation methods are proposed.

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, 2015

The 2011 Tohoku Earthquake ruptured several asperities at the same time, which generated a large ... more The 2011 Tohoku Earthquake ruptured several asperities at the same time, which generated a large scale and long period ground motion. Recently the higher level of the earthquake ground motion is considered in structural design, and the nonlinearity characteristics such as large plasticity or fracture of members are inevitable issues in seismic performance evaluation of the steel structures. This paper presents the seismic performance of the braced frames is assessed by the time history response analysis program taking fracture of the end of beams and braces into account. The incremental dynamic analysis (IDA) is hired, in order to grasp the ultimate state under extremely large ground motions. The fragility curve was constituted from the analysis results, which provides the member fracture has definitely effect on the seismic performance of the braced frames.

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, 2017

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, 2014

Although truss towers used for telecommunication, electric power transportation, supporting struc... more Although truss towers used for telecommunication, electric power transportation, supporting structures for smokestacks in power plants have been designed against wind loads, a higher level of safety is recently required because of the increase of anticipated large seismic inputs. The ultimate strength of these structures is governed by tubular member buckling which is easily led to member fracture. This paper proposes the post-fracture analysis methods for truss structures composed with tubular members of large diameter-to-thickness ratios, and study on the collapse mechanism of such truss towers after the buckling and fracture of main columns and diagonals are investigated, using IDA analyses taking these member fractures into account.

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, Aug 1, 2023

This paper investigates the effect of the span of cantilevered RC wall, the in-plane stiffness of... more This paper investigates the effect of the span of cantilevered RC wall, the in-plane stiffness of the roof, the layout of friction damper support on both the response control of cantilevered RC walls in RC gymnasiums with metal spatial roofs and the proposed response evaluation method. According to the response history analysis results, the proposed method was proved to be available on various RC gymnasiums and the evaluation formula of the column base moment of the cantilevered RC walls was modified following the appropriate moment diagram.

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, Jun 30, 2021

Design procedure for out-of-plane response control of a cantilevered RC wall connected by roller ... more Design procedure for out-of-plane response control of a cantilevered RC wall connected by roller supports to metal spatial roof was proposed. This design procedure is carefully formulated based on Japanese structural engineer's practice. The design equation is derived from both equivalent linear approach simulating damping effect and distributed parameter system where a cantilevered RC wall is modeled as single beam or single plate. The accuracy is validated against numerical simulations of damaged school gymnasia and a shake table testing of 1/2.5-scaled model of school gymnasium.

Journal of Structural and Construction Engineering (Transactions of AIJ), 2021

The effect of shear force on the historic properties of timber-steel hybrid connections between a... more The effect of shear force on the historic properties of timber-steel hybrid connections between an H-shaped steel and a laminated timber was investigated, and several bending tests of monotonic and cyclic loading were conducted for two different cross-sectional dimensions of the joint with both side flanges fixed by lag screws. Little significant effect of the shear force was observed, and the proposed connections were found to have ideal fracture behavior, stable hysteresis properties and superior plastic deformation capacities.

Journal of Structural and Construction Engineering (Transactions of AIJ), 2018

Numerous steel roof bearings in RC gymnasia were damaged at the 2011 Tohoku and 2016 Kumamoto Ear... more Numerous steel roof bearings in RC gymnasia were damaged at the 2011 Tohoku and 2016 Kumamoto Earthquake, mainly due to the out-of-plane response of cantilevered RC walls. Although the authors confirmed the longitudinal response reduction effect of the cantilevered RC walls by friction damper bearings, the transverse response was not examined. In this paper, dynamic loading tests of a sliding bearing with PTFE sheets, a friction damper bearing, and a rubber sheet bearing are conducted. The response of the RC walls in the longitudinal and traverse direction is calculated by numerical simulation using bearing hysteresis loops constituted by test results.

Journal of Structural and Construction Engineering (Transactions of AIJ), 2006

Journal of Structural and Construction Engineering (Transactions of AIJ), 2017

Recently, there have been worries concerning the risk of fracture at the end of beams in the exis... more Recently, there have been worries concerning the risk of fracture at the end of beams in the existing steel building frames during a long period and long duration motion caused by the Nankai-trough great earthquake expected near the future. Researchers proposed several simple evaluation methods to capture damages at the end of beams. In this paper, damages at beam-ends in a high rise steel building during a long period and long duration motion are considered taking fracture of braces into account. And the simple damage evaluation method which is more accurate than ever are proposed.

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, 2004

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, 2017

The authors conducted a series of experimental studies on the response characteristics of control... more The authors conducted a series of experimental studies on the response characteristics of controlled rocking systems. This system comprises components that include a rocking frame, post-tensioning (PT) anchorages, and elasto-plastic damper, eliminating the residual deformation after the earthquake. In this paper, detailed and accurate analysis to simulate the system is utilized to clarify the details of local and global responses and theier relationship. The use of elasto-plastic damper requires the PT anchorages, which is found to limit performance of the rocking system. In order to explore possible enhancement, the visco-elastic damper is assumed instead, and its accurate analysis model is developed based on the damper test. The performance of the rocking system with the viscoelastic damper is analytically evaluated and the extent of improved performance is discussed.

Key Engineering Materials, Feb 1, 2018

The authors have proposed a method to assess local fracture of concentric braced frames under cyc... more The authors have proposed a method to assess local fracture of concentric braced frames under cyclic loading from global member results termed the Direct Local Strain Evaluation Method. In this method there is no need to use detailed member shell models to estimate the strain at the fracture point in the braces. This enables accurate time history response analysis using less computationally intensive stick models, while including the effect of local member fracture. However, up to now, the accuracy of the proposed method has only been validated under static loading. This research validates the proposed method with dynamic numeric and shake table testing. The proposed method is effective in simulating the braced frame response including the brace fracture under dynamic loading.

Journal of Structural and Construction Engineering (Transactions of AIJ)

This paper presents design recommendations for optimal seismic response control of damped braced ... more This paper presents design recommendations for optimal seismic response control of damped braced tube system with focus on cost performance of introducing energy-dissipation devices. According to the results, 1) braced tube structure should be designed so that coupled-shear-wall-like vibration modes are predominant to obtain highly damping ratio and better cost performance of dampers, 2) oil damper should be introduced to obtain highly damping ratio, 3) BRB has good cost performance about seismic response reduction and can be used to reduce damper costs.

Journal of Structural and Construction Engineering (Transactions of AIJ)

Simple seismic damage evaluation of the steel tower for power transmission considering global buc... more Simple seismic damage evaluation of the steel tower for power transmission considering global buckling of braces was proposed, which can be used as an index for seismic performance screening of the existing steel towers focusing on the large seismic ground motions. The evaluation index value can be calculated simply by defining seismic performance curves and frame limit displacements of typical steel towers and based on the energy balance concept, and it can be easily used in Japanese transmission structural engineer's practice in which stress calculation method based on Cremona diagram is common.

Journal of Structural and Construction Engineering (Transactions of AIJ), 2019

In our previous paper, the static rigidity and the flexural strength at the joint of the lattice ... more In our previous paper, the static rigidity and the flexural strength at the joint of the lattice shell with the timber steel hybrid connection were clarified by static experiments and their effect on the buckling behavior of the entire roof was revealed by elastic buckling analysis. Here we examine the influence of the rotational stiffness of the connections on natural oscillation and earthquake response characteristics. Also the accuracy of the response spectrum evaluation using CQC method and the equivalent static seismic load are verified, followed by a simplified evaluation method proposal for the effect of rotational stiffness at connections.

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, Jul 1, 2023

In 2011, many roof bearings in large span facilities were damaged severely by the Pacific coast o... more In 2011, many roof bearings in large span facilities were damaged severely by the Pacific coast of Tohoku earthquake. Some of them were designed as slide bearings to release the thrust caused by the weight of roof. In ball-jointed system truss roof, bearings are subjected to horizontal movement and rotation since the roof structure has insufficient bending stiffness. In this study, we conducted the cyclic loading tests on conventional roof bearings and analyzed the observed behavior. In addition, we derived functions which express horizontal force in relation to horizontal displacement and rotation and verified by comparing with the test results.

IEEE Journal of Solid-state Circuits, Mar 24, 2005

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, Dec 1, 2022

This paper investigated the dynamic response characteristic with focus on damped slit configurati... more This paper investigated the dynamic response characteristic with focus on damped slit configuration of damped braced tube systems with oil dampers. According to the results, 1) damped braced tube system has over 10% 1st to 3rd damping ratio, 2) while the displacement and acceleration responses are simultaneously reduced up to maximized 1st mode damping ratio, the acceleration reduction effect may be getting worse after the peak, 3) while uniform damper distribution contributes to better damping performance, centralized damper distribution contributes to better period reduction.

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, 2005

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, Nov 1, 2022

While BRBs using laminated timber as a restrainer have been widely studied, timber restrainers ha... more While BRBs using laminated timber as a restrainer have been widely studied, timber restrainers have lower stiffness than steel restrainers with higher risk of fragile crack failure, it is necessary to consider the safety factor of global buckling, global stability of restrainer ends and local bulging failure at restrainer. In this study, a wide range of mock-up loading tests on BRBs with timber restrainer were carried out with different core-to-restraint compositions, in-plane and out-of-plane clearances, with and without core additional steel plates, and with different boundary conditions. Their exhibited failure modes are carefully studied and evaluation methods are proposed.

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, 2015

The 2011 Tohoku Earthquake ruptured several asperities at the same time, which generated a large ... more The 2011 Tohoku Earthquake ruptured several asperities at the same time, which generated a large scale and long period ground motion. Recently the higher level of the earthquake ground motion is considered in structural design, and the nonlinearity characteristics such as large plasticity or fracture of members are inevitable issues in seismic performance evaluation of the steel structures. This paper presents the seismic performance of the braced frames is assessed by the time history response analysis program taking fracture of the end of beams and braces into account. The incremental dynamic analysis (IDA) is hired, in order to grasp the ultimate state under extremely large ground motions. The fragility curve was constituted from the analysis results, which provides the member fracture has definitely effect on the seismic performance of the braced frames.

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, 2017

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, 2014

Although truss towers used for telecommunication, electric power transportation, supporting struc... more Although truss towers used for telecommunication, electric power transportation, supporting structures for smokestacks in power plants have been designed against wind loads, a higher level of safety is recently required because of the increase of anticipated large seismic inputs. The ultimate strength of these structures is governed by tubular member buckling which is easily led to member fracture. This paper proposes the post-fracture analysis methods for truss structures composed with tubular members of large diameter-to-thickness ratios, and study on the collapse mechanism of such truss towers after the buckling and fracture of main columns and diagonals are investigated, using IDA analyses taking these member fractures into account.

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, Aug 1, 2023

This paper investigates the effect of the span of cantilevered RC wall, the in-plane stiffness of... more This paper investigates the effect of the span of cantilevered RC wall, the in-plane stiffness of the roof, the layout of friction damper support on both the response control of cantilevered RC walls in RC gymnasiums with metal spatial roofs and the proposed response evaluation method. According to the response history analysis results, the proposed method was proved to be available on various RC gymnasiums and the evaluation formula of the column base moment of the cantilevered RC walls was modified following the appropriate moment diagram.

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, Jun 30, 2021

Design procedure for out-of-plane response control of a cantilevered RC wall connected by roller ... more Design procedure for out-of-plane response control of a cantilevered RC wall connected by roller supports to metal spatial roof was proposed. This design procedure is carefully formulated based on Japanese structural engineer's practice. The design equation is derived from both equivalent linear approach simulating damping effect and distributed parameter system where a cantilevered RC wall is modeled as single beam or single plate. The accuracy is validated against numerical simulations of damaged school gymnasia and a shake table testing of 1/2.5-scaled model of school gymnasium.

Journal of Structural and Construction Engineering (Transactions of AIJ), 2021

The effect of shear force on the historic properties of timber-steel hybrid connections between a... more The effect of shear force on the historic properties of timber-steel hybrid connections between an H-shaped steel and a laminated timber was investigated, and several bending tests of monotonic and cyclic loading were conducted for two different cross-sectional dimensions of the joint with both side flanges fixed by lag screws. Little significant effect of the shear force was observed, and the proposed connections were found to have ideal fracture behavior, stable hysteresis properties and superior plastic deformation capacities.

Journal of Structural and Construction Engineering (Transactions of AIJ), 2018

Numerous steel roof bearings in RC gymnasia were damaged at the 2011 Tohoku and 2016 Kumamoto Ear... more Numerous steel roof bearings in RC gymnasia were damaged at the 2011 Tohoku and 2016 Kumamoto Earthquake, mainly due to the out-of-plane response of cantilevered RC walls. Although the authors confirmed the longitudinal response reduction effect of the cantilevered RC walls by friction damper bearings, the transverse response was not examined. In this paper, dynamic loading tests of a sliding bearing with PTFE sheets, a friction damper bearing, and a rubber sheet bearing are conducted. The response of the RC walls in the longitudinal and traverse direction is calculated by numerical simulation using bearing hysteresis loops constituted by test results.

Journal of Structural and Construction Engineering (Transactions of AIJ), 2006

Journal of Structural and Construction Engineering (Transactions of AIJ), 2017

Recently, there have been worries concerning the risk of fracture at the end of beams in the exis... more Recently, there have been worries concerning the risk of fracture at the end of beams in the existing steel building frames during a long period and long duration motion caused by the Nankai-trough great earthquake expected near the future. Researchers proposed several simple evaluation methods to capture damages at the end of beams. In this paper, damages at beam-ends in a high rise steel building during a long period and long duration motion are considered taking fracture of braces into account. And the simple damage evaluation method which is more accurate than ever are proposed.

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, 2004

Nihon Kenchiku Gakkai kōzō-kei ronbunshū, 2017

The authors conducted a series of experimental studies on the response characteristics of control... more The authors conducted a series of experimental studies on the response characteristics of controlled rocking systems. This system comprises components that include a rocking frame, post-tensioning (PT) anchorages, and elasto-plastic damper, eliminating the residual deformation after the earthquake. In this paper, detailed and accurate analysis to simulate the system is utilized to clarify the details of local and global responses and theier relationship. The use of elasto-plastic damper requires the PT anchorages, which is found to limit performance of the rocking system. In order to explore possible enhancement, the visco-elastic damper is assumed instead, and its accurate analysis model is developed based on the damper test. The performance of the rocking system with the viscoelastic damper is analytically evaluated and the extent of improved performance is discussed.

Key Engineering Materials, Feb 1, 2018

The authors have proposed a method to assess local fracture of concentric braced frames under cyc... more The authors have proposed a method to assess local fracture of concentric braced frames under cyclic loading from global member results termed the Direct Local Strain Evaluation Method. In this method there is no need to use detailed member shell models to estimate the strain at the fracture point in the braces. This enables accurate time history response analysis using less computationally intensive stick models, while including the effect of local member fracture. However, up to now, the accuracy of the proposed method has only been validated under static loading. This research validates the proposed method with dynamic numeric and shake table testing. The proposed method is effective in simulating the braced frame response including the brace fracture under dynamic loading.

Journal of Structural and Construction Engineering (Transactions of AIJ)

This paper presents design recommendations for optimal seismic response control of damped braced ... more This paper presents design recommendations for optimal seismic response control of damped braced tube system with focus on cost performance of introducing energy-dissipation devices. According to the results, 1) braced tube structure should be designed so that coupled-shear-wall-like vibration modes are predominant to obtain highly damping ratio and better cost performance of dampers, 2) oil damper should be introduced to obtain highly damping ratio, 3) BRB has good cost performance about seismic response reduction and can be used to reduce damper costs.

Journal of Structural and Construction Engineering (Transactions of AIJ)

Simple seismic damage evaluation of the steel tower for power transmission considering global buc... more Simple seismic damage evaluation of the steel tower for power transmission considering global buckling of braces was proposed, which can be used as an index for seismic performance screening of the existing steel towers focusing on the large seismic ground motions. The evaluation index value can be calculated simply by defining seismic performance curves and frame limit displacements of typical steel towers and based on the energy balance concept, and it can be easily used in Japanese transmission structural engineer's practice in which stress calculation method based on Cremona diagram is common.

Journal of Structural and Construction Engineering (Transactions of AIJ), 2019

In our previous paper, the static rigidity and the flexural strength at the joint of the lattice ... more In our previous paper, the static rigidity and the flexural strength at the joint of the lattice shell with the timber steel hybrid connection were clarified by static experiments and their effect on the buckling behavior of the entire roof was revealed by elastic buckling analysis. Here we examine the influence of the rotational stiffness of the connections on natural oscillation and earthquake response characteristics. Also the accuracy of the response spectrum evaluation using CQC method and the equivalent static seismic load are verified, followed by a simplified evaluation method proposal for the effect of rotational stiffness at connections.