The Experts below are selected from a list of 3054 Experts worldwide ranked by ideXlab platform

Gu Pei-hua - One of the best experts on this subject based on the ideXlab platform.

  • Research on robust design of the oblique five-Hinge Joint-double toggle clamping unit on cup makers
    Journal of Engineering Design, 2010
    Co-Authors: Gu Pei-hua
    Abstract:

    Aiming at the problem that the large number of variables in design and manufacture of the oblique five-Hinge Joint-double toggle clamping unit of cup makers,hardness in its assembling,wide range of the variation of its functional objective value,the necessity and feasibility of its robust design was analyzed.An optimization model was established according to the analytical robust design theory,and the system variables were optimized to decrease the variation of the system objective value.Finally,the sensitivity matrix was calculated to indicate the relationship between sensitivity and every design system variable.The research results reveal that the critical angle,oblique angle and the size of forward-wrist pin,and backward-wrist pin are the most crucial to determine the quality of the system.It provides an objective basis on how to improve systems' accuracy selectively,which can be employed in engineering practice.

Gregory A Macrae - One of the best experts on this subject based on the ideXlab platform.

  • experimental studies on belleville springs use in the sliding Hinge Joint connection
    Journal of Constructional Steel Research, 2019
    Co-Authors: Shahab Ramhormozian, Gregory A Macrae, Charles G Clifton, George P Davet, Hsen Han Khoo
    Abstract:

    Abstract The Sliding Hinge Joint (SHJ) is a low damage beam-to-column connection developed for and widely used in seismic moment-resisting steel frames (MRSFs). The asymmetric friction connection (AFC) is the SHJ's friction sliding energy dissipating component, which has also been used in other seismic resisting structural systems. In current practice, the AFC bolts are yielded at installation by the method of bolt tightening, and they are subjected to moment, shear, and axial force (MVP) interaction during stable sliding. Hence the AFC bolts tension, and as a result, SHJ elastic strength will be reduced after sliding cycles. A remedy to this post-sliding strength reduction could be installing the AFC bolts in the elastic range in conjunction with using Belleville springs (BeSs) to maintain the clamping force, but at the potential cost of deteriorating the SHJ self-centering capability. This paper describes nine real-scale SHJ's AFC component tests at quasi-static and dynamic rates of displacement controlled loading, with bolts either tightened in the elastic range using no BeSs as well as with four different configurations of BeSs which are deliberately not fully deflected at installation, to avoid the system self-centering capability deterioration and to minimize the additional imposed tension on the AFC bolts during stable sliding. It is concluded that using partially deflected BeSs with sufficient axial deformation to reach the installed bolt tension, with these being installed at both head and nut sides of the AFC bolts, will reduce the post-sliding clamping force loss, improve the self-centering capability, increase the system coefficient of friction, reduce the additional imposed tension on the AFC bolts during stable sliding due to prying actions and/or MVP interactions, and reduce the severity of the sliding surfaces' wearing.

  • The Sliding Hinge Joint: Final Steps towards an Optimum Low Damage Seismic-Resistant Steel System
    Key Engineering Materials, 2018
    Co-Authors: Shahab Ramhormozian, Gregory A Macrae, George Charles Clifton, Hsen Han Khoo
    Abstract:

    The Sliding Hinge Joint with Asymmetric Friction Connectors (SHJ), to give its full name, is a semi-rigid moment resisting Joint used between the beams and columns of a moment-resisting steel frame and also at the column base between the column and the ground. It’s performance is intended to be as follows: 1) On completion of construction, rigid under serviceability limit state conditions, 2) During a severe earthquake, allowing controlled rotation between the column and the beam or foundation on designated friction sliding planes within the connection, then 3) Returning to its rigid in-service condition at the end of the severe shaking with the building returning to its pre-earthquake position (self-centering). During its development and proof of concept through large scale testing, the initial results showed that the SHJ as originally designed and detailed performs 1) and 2) very well, but the bolts in the friction sliding planes loose much of their original installed bolt tension during significant sliding, lowering the level at which rotation within the Joint will occur post severe earthquake. A concerted research programme of component testing, analytical model development and numerical modelling in recent years has developed solutions to the bolt tension loss issue as well as enhanced the Joint’s performance to deliver dependable self-centering capability for the building. This work marks the final steps towards developing an optimum low damage seismic-resisting steel moment frame system. This paper presents key findings from the research work and general recommendations for the optimum performing sliding Hinge Joint.

  • The Asymmetric Friction Connection with Belleville Springs in the Sliding Hinge Joint
    2014
    Co-Authors: Shahab Ramhormozian, George Charles Clifton, Gregory A Macrae
    Abstract:

    The Sliding Hinge Joint (SHJ) is a Joint for moment resisting steel frame (MRSF) seismic-resisting systems. It is ideally intended to be rigid under serviceability limit state (SLS) conditions. For greater shaking, up to the ultimate limit state (ULS), rotation between the column and beam is expected. At the end of the shaking the Joint is expected to seize up and become rigid again. A key component in the sliding Hinge Joint is the asymmetric friction connection (AFC) which allows large beam-column rotation with minimal damage through sliding. However, previous research has shown that, after a severe earthquake, the post sliding strength and stiffness of the SHJ connection as currently applied is considerably reduced, such that re-tightening or replacement of the bolts is likely to be needed. This is because the AFC bolts lose part of their initial tension during Joint sliding. Hence the Joint falls short of meeting one of the key original low damage performance requirements of not requiring any structural intervention following a severe earthquake. A remedy to this shortcoming could be using Belleville springs in the AFC. However, the introduction of Belleville Springs potentially reduces the self centering ability of the building and the impact of this effect must be considered. Belleville springs are truncated conical washer-type elements that compress elastically to an accurately defined level of force. When the bolt relaxes, the Belleville spring pushes out to maintain very close to the installed level of tension. The behaviour and sliding shear capacity of the AFC with Belleville springs is to be investigated in this project and will be presented in this paper considering different configurations using a plastic theory based bolt model. A method of installing the bolts using Belleville springs is then proposed. The predicted effects of using the AFC with Belleville springs on the SHJ characteristics such as dynamic self centering properties are also discussed. Finally, the proposed research program to determine the performance of AFC’s with Belleville springs and their influence on the overall building performance is outlined.

  • BEHAVIOUR OF THE BOTTOM AND TOP FLANGE PLATES IN THE SLIDING Hinge Joint
    Bulletin of the New Zealand Society for Earthquake Engineering, 2013
    Co-Authors: Hsen Han Khoo, John Butterworth, Charles Clifton, C. K. Seal, Gregory A Macrae
    Abstract:

    SUMMARY The Sliding Hinge Joint is a low damage beam-column connection used in steel moment resisting frames. It dissipates energy through sliding in Asymmetric Friction Connections (AFCs) in the bottom web and bottom flange bolt groups. The AFC confines earthquake induced damage to bolts that can be retightened or replaced following a major earthquake. The other Joint components sustain negligible damage and would be kept in service and may thus be subjected to further earthquake shaking during the lifetime of the building. The bottom and top flange plates are also subject to inelastic action about their minor axis under Joint rotation. This study evaluates the behaviour of the bottom and top flange plates to determine the weld and plate susceptibility to low-cycle fatigue failure. The basic flange plate deformation was approximated by an arc, with the effects of shear slip considered to obtain estimates of likely strain demands. It was shown that even in the most critical case the fatigue life is more than six times the demand expected in a design level earthquake. As a result, it is concluded that properly designed, detailed and connected flange plates are not prone to low-cycle fatigue failure.

  • experimental study of full scale self centering sliding Hinge Joint connections with friction ring springs
    Journal of Earthquake Engineering, 2013
    Co-Authors: Hsen Han Khoo, John Butterworth, Charles Clifton, Gregory A Macrae
    Abstract:

    This article presents 10 tests on a self-centering Sliding Hinge Joint (SHJ) subassembly. The flexural capacity was generated with a combination of ring springs and Asymmetric Friction Connections, with the proportion varied between tests. The Joints produced stable and repeatable hysteretic behavior and minimal damage to the floor slab, with self-centering capability improving with increasing ring spring contribution. There was negligible difference between tests undertaken at static and seismic-dynamic rates of loading. The SHJ had a 20% reduction in strength under a near fault pulse type motion. A simple mathematical model of the SCSHJ rotational behavior is also developed.

Hsen Han Khoo - One of the best experts on this subject based on the ideXlab platform.

  • experimental studies on belleville springs use in the sliding Hinge Joint connection
    Journal of Constructional Steel Research, 2019
    Co-Authors: Shahab Ramhormozian, Gregory A Macrae, Charles G Clifton, George P Davet, Hsen Han Khoo
    Abstract:

    Abstract The Sliding Hinge Joint (SHJ) is a low damage beam-to-column connection developed for and widely used in seismic moment-resisting steel frames (MRSFs). The asymmetric friction connection (AFC) is the SHJ's friction sliding energy dissipating component, which has also been used in other seismic resisting structural systems. In current practice, the AFC bolts are yielded at installation by the method of bolt tightening, and they are subjected to moment, shear, and axial force (MVP) interaction during stable sliding. Hence the AFC bolts tension, and as a result, SHJ elastic strength will be reduced after sliding cycles. A remedy to this post-sliding strength reduction could be installing the AFC bolts in the elastic range in conjunction with using Belleville springs (BeSs) to maintain the clamping force, but at the potential cost of deteriorating the SHJ self-centering capability. This paper describes nine real-scale SHJ's AFC component tests at quasi-static and dynamic rates of displacement controlled loading, with bolts either tightened in the elastic range using no BeSs as well as with four different configurations of BeSs which are deliberately not fully deflected at installation, to avoid the system self-centering capability deterioration and to minimize the additional imposed tension on the AFC bolts during stable sliding. It is concluded that using partially deflected BeSs with sufficient axial deformation to reach the installed bolt tension, with these being installed at both head and nut sides of the AFC bolts, will reduce the post-sliding clamping force loss, improve the self-centering capability, increase the system coefficient of friction, reduce the additional imposed tension on the AFC bolts during stable sliding due to prying actions and/or MVP interactions, and reduce the severity of the sliding surfaces' wearing.

  • The Sliding Hinge Joint: Final Steps towards an Optimum Low Damage Seismic-Resistant Steel System
    Key Engineering Materials, 2018
    Co-Authors: Shahab Ramhormozian, Gregory A Macrae, George Charles Clifton, Hsen Han Khoo
    Abstract:

    The Sliding Hinge Joint with Asymmetric Friction Connectors (SHJ), to give its full name, is a semi-rigid moment resisting Joint used between the beams and columns of a moment-resisting steel frame and also at the column base between the column and the ground. It’s performance is intended to be as follows: 1) On completion of construction, rigid under serviceability limit state conditions, 2) During a severe earthquake, allowing controlled rotation between the column and the beam or foundation on designated friction sliding planes within the connection, then 3) Returning to its rigid in-service condition at the end of the severe shaking with the building returning to its pre-earthquake position (self-centering). During its development and proof of concept through large scale testing, the initial results showed that the SHJ as originally designed and detailed performs 1) and 2) very well, but the bolts in the friction sliding planes loose much of their original installed bolt tension during significant sliding, lowering the level at which rotation within the Joint will occur post severe earthquake. A concerted research programme of component testing, analytical model development and numerical modelling in recent years has developed solutions to the bolt tension loss issue as well as enhanced the Joint’s performance to deliver dependable self-centering capability for the building. This work marks the final steps towards developing an optimum low damage seismic-resisting steel moment frame system. This paper presents key findings from the research work and general recommendations for the optimum performing sliding Hinge Joint.

  • BEHAVIOUR OF THE BOTTOM AND TOP FLANGE PLATES IN THE SLIDING Hinge Joint
    Bulletin of the New Zealand Society for Earthquake Engineering, 2013
    Co-Authors: Hsen Han Khoo, John Butterworth, Charles Clifton, C. K. Seal, Gregory A Macrae
    Abstract:

    SUMMARY The Sliding Hinge Joint is a low damage beam-column connection used in steel moment resisting frames. It dissipates energy through sliding in Asymmetric Friction Connections (AFCs) in the bottom web and bottom flange bolt groups. The AFC confines earthquake induced damage to bolts that can be retightened or replaced following a major earthquake. The other Joint components sustain negligible damage and would be kept in service and may thus be subjected to further earthquake shaking during the lifetime of the building. The bottom and top flange plates are also subject to inelastic action about their minor axis under Joint rotation. This study evaluates the behaviour of the bottom and top flange plates to determine the weld and plate susceptibility to low-cycle fatigue failure. The basic flange plate deformation was approximated by an arc, with the effects of shear slip considered to obtain estimates of likely strain demands. It was shown that even in the most critical case the fatigue life is more than six times the demand expected in a design level earthquake. As a result, it is concluded that properly designed, detailed and connected flange plates are not prone to low-cycle fatigue failure.

  • experimental study of full scale self centering sliding Hinge Joint connections with friction ring springs
    Journal of Earthquake Engineering, 2013
    Co-Authors: Hsen Han Khoo, John Butterworth, Charles Clifton, Gregory A Macrae
    Abstract:

    This article presents 10 tests on a self-centering Sliding Hinge Joint (SHJ) subassembly. The flexural capacity was generated with a combination of ring springs and Asymmetric Friction Connections, with the proportion varied between tests. The Joints produced stable and repeatable hysteretic behavior and minimal damage to the floor slab, with self-centering capability improving with increasing ring spring contribution. There was negligible difference between tests undertaken at static and seismic-dynamic rates of loading. The SHJ had a 20% reduction in strength under a near fault pulse type motion. A simple mathematical model of the SCSHJ rotational behavior is also developed.

  • development of the self centering sliding Hinge Joint with friction ring springs
    Journal of Constructional Steel Research, 2012
    Co-Authors: Gregory A Macrae, John Butterworth, Hsen Han Khoo, Charles Clifton, Sean Gledhill, Geoffrey Sidwell
    Abstract:

    article i nfo The Sliding Hinge Joint (SHJ) is a low-damage beam-column connection used in steel moment-resisting frames. It allows large beam-column rotation with minimal damage through sliding in asymmetric friction connections. It is however, subject to elastic strength and stiffness degradation and potential residual defor- mations under earthquake shaking and inelastic action. This paper describes the development of the self-centering SHJ incorporating ring springs installed to the beam bottom flange to improve the dynamic re-centering properties and reduce strength degradation. Five 10-storey frames with ring springs generating up to 50% of Joint moment capacity were studied analytically using a suite of 10 earthquake records. Ring spring contribution of 40% improved the self-centering properties, resulting in residual drifts less than 0.1% under design level shaking. They also reduced strength degradation.

John Butterworth - One of the best experts on this subject based on the ideXlab platform.

  • BEHAVIOUR OF THE BOTTOM AND TOP FLANGE PLATES IN THE SLIDING Hinge Joint
    Bulletin of the New Zealand Society for Earthquake Engineering, 2013
    Co-Authors: Hsen Han Khoo, John Butterworth, Charles Clifton, C. K. Seal, Gregory A Macrae
    Abstract:

    SUMMARY The Sliding Hinge Joint is a low damage beam-column connection used in steel moment resisting frames. It dissipates energy through sliding in Asymmetric Friction Connections (AFCs) in the bottom web and bottom flange bolt groups. The AFC confines earthquake induced damage to bolts that can be retightened or replaced following a major earthquake. The other Joint components sustain negligible damage and would be kept in service and may thus be subjected to further earthquake shaking during the lifetime of the building. The bottom and top flange plates are also subject to inelastic action about their minor axis under Joint rotation. This study evaluates the behaviour of the bottom and top flange plates to determine the weld and plate susceptibility to low-cycle fatigue failure. The basic flange plate deformation was approximated by an arc, with the effects of shear slip considered to obtain estimates of likely strain demands. It was shown that even in the most critical case the fatigue life is more than six times the demand expected in a design level earthquake. As a result, it is concluded that properly designed, detailed and connected flange plates are not prone to low-cycle fatigue failure.

  • experimental study of full scale self centering sliding Hinge Joint connections with friction ring springs
    Journal of Earthquake Engineering, 2013
    Co-Authors: Hsen Han Khoo, John Butterworth, Charles Clifton, Gregory A Macrae
    Abstract:

    This article presents 10 tests on a self-centering Sliding Hinge Joint (SHJ) subassembly. The flexural capacity was generated with a combination of ring springs and Asymmetric Friction Connections, with the proportion varied between tests. The Joints produced stable and repeatable hysteretic behavior and minimal damage to the floor slab, with self-centering capability improving with increasing ring spring contribution. There was negligible difference between tests undertaken at static and seismic-dynamic rates of loading. The SHJ had a 20% reduction in strength under a near fault pulse type motion. A simple mathematical model of the SCSHJ rotational behavior is also developed.

  • development of the self centering sliding Hinge Joint with friction ring springs
    Journal of Constructional Steel Research, 2012
    Co-Authors: Gregory A Macrae, John Butterworth, Hsen Han Khoo, Charles Clifton, Sean Gledhill, Geoffrey Sidwell
    Abstract:

    article i nfo The Sliding Hinge Joint (SHJ) is a low-damage beam-column connection used in steel moment-resisting frames. It allows large beam-column rotation with minimal damage through sliding in asymmetric friction connections. It is however, subject to elastic strength and stiffness degradation and potential residual defor- mations under earthquake shaking and inelastic action. This paper describes the development of the self-centering SHJ incorporating ring springs installed to the beam bottom flange to improve the dynamic re-centering properties and reduce strength degradation. Five 10-storey frames with ring springs generating up to 50% of Joint moment capacity were studied analytically using a suite of 10 earthquake records. Ring spring contribution of 40% improved the self-centering properties, resulting in residual drifts less than 0.1% under design level shaking. They also reduced strength degradation.

  • influence of steel shim hardness on the sliding Hinge Joint performance
    Journal of Constructional Steel Research, 2012
    Co-Authors: Hsen Han Khoo, Gregory A Macrae, John Butterworth, Charles Clifton, George Ferguson
    Abstract:

    Abstract The Sliding Hinge Joint is a flexural connection designed for use at the ends of beams in steel moment resisting frames. It is an asymmetric friction connection, where energy is dissipated through sliding in slotted bolted connections in the beam bottom flange. The friction resistance and the repeatability of the hysteretic force displacement curves are dependent on the type of shim used. Brass or mild steel shims have been researched and used in construction to date. This paper describes tests on the sliding components conducted to investigate the use of steel shims of different hardness. The materials tested were mild steel, high strength quenched and tempered steel, and abrasion resistant steel. The beam and cleats which these shims slid against were Grade 300 mild steel. The specimens were tested dynamically at earthquake rates of loading. The abrasion resistant steel, the hardest material, produced the most stable and consistent sliding characteristics for all displacement cycles on different specimens. It also had the least material wear and the highest friction capacity per bolt. Compared to brass, high strength steels are more readily available, less costly, more easily erected, and less susceptible to corrosion, making them a preferred solution.

  • the sliding Hinge Joint moment connection
    Bulletin of the New Zealand National Society for Earthquake Engineering, 2010
    Co-Authors: Gregory A Macrae, Charles G Clifton, Hamish Mackinven, Nandor Mago, John Butterworth, S Pampanin
    Abstract:

    SUMMARY A new friction moment Joint for steel framed structures is described. It has a similar cost to conventional construction and is designed such that there is negligible damage to the frame or slabs. Experimental testing shows that steel, brass or aluminium shims can provide satisfactory friction resistance and that there is almost no damage to the frame during design level displacements. A method for establishing the dependable friction force is developed considering construction tolerances and bolt moment-axial-force-shear interaction. A design methodology for the Joint and a design example are provided.

Yu-qing Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Studies on the Changes in the Parameters Stability of Hinge Joint Concrete Block Slope
    Applied Mechanics and Materials, 2012
    Co-Authors: Yu-qing Zhang, Yong Ning Mi, Jin Ting Zhao, Zhen Guo Wang, Lu Wang, Xin Shao
    Abstract:

    Slope protection is to ensure the security of levee foundation engineering. This article take the actual project--the Bird Island Park of Shenyang City Hinge Joint concrete block slope,as an example, use of FLAC software and strengthen reduction method, calculated by 29°slope angle, 45kg block the effect slope stability factor of safety. In view of the different parameters (slope, block quality, bulk density, cohesion force, internal friction angle), discussion of various parameters on slope stability of safety coefficient, and obtained the best slope and block quality combination, so as to the slope protection design and application reference.

  • Research on Stability Analysis of the Hinge Joint Concrete Block Slope under Seepage Function
    Advanced Materials Research, 2012
    Co-Authors: Yu-qing Zhang, Lin Zhao, Kan Liu, Guo Li Wang
    Abstract:

    The actual project—the Bird Island Park in Shenyang, an example of Hinge Joint concrete block revetment ,using the FLAC analysis software, and the finite difference method percolation theory to calculate the 29 slope angle the role of a 45kg block under the action of the seepage stability of the slope. Variation in water head discussed in further detail and the role of the different blocks on the slope stability of the quality of the impact of the slope to provide a reference design and application.

  • Study on Seepage under the Hinge Joint Stability of Concrete Block Slope
    Applied Mechanics and Materials, 2011
    Co-Authors: Yu-qing Zhang, Lu Wang, Xin Wang
    Abstract:

    Slope is the wide range of large in channel works to ensure the safety of critical infrastructure.The actual project—the Bird Island Park in Shenyang, an example of Hinge Joint concrete block revetment ,using the FLAC analysis software, and the finite difference method percolation theory to calculate the 29 slope angle the role of a 45kg block under the action of the seepage stability of the slope. Variation in water level discussed in further detail and the role of the different blocks on the slope stability of the quality of the impact of the slope to provide a reference design and application.

  • Study on Strength Reduction Method Based on Hinge Joint Concrete Block Slope Stability
    Applied Mechanics and Materials, 2011
    Co-Authors: Yu-qing Zhang, Lin Zhao, Rong Hua Sun, Ying Zhang
    Abstract:

    Slope protection is to ensure the safety of River embankment important infrastructure projects.the actual project--the Bird Island Park in Shenyang, an example of Hinge Joint concrete block revetment,Using the FLAC analysis software, and the finite difference method percolation theory to calculate the 29° slope angle the role of a 45kg block under the action of Slope stability safety factor,Further discussed in detail the different blocks of different slope and slope stability on the role of the quality factor of safety effects, and draw the best slope and block quality portfolio, which is the slope of reference designs and applications.