The Experts below are selected from a list of 31893 Experts worldwide ranked by ideXlab platform
Gernay Thomas - One of the best experts on this subject based on the ideXlab platform.
-
Post-blast fire resistance of low-rise buildings through membrane action of composite floor slabs
2017Co-Authors: Haase Bryce, Elhami Khorasani Negar, Gernay ThomasAbstract:Sever fires in buildings can lead to local failures, instability, partial or total collapse of the structure. In majority of the times, fire is a secondary event, after blast or impact, while the building has experienced some damage. Examples of widely known events include the 1968 Ronan Point collapse in the UK, the 1995 Oklahoma City bombing, the World Trade Center Collapse in New York in 2001, the 2014 collapse of a building at New York’s Harlem neighborhood due to a gas explosion, and the recent 2015 collapse of a building at New York’s East Village also due to a gas explosion. The initial shock to the building can be conservatively modeled by removing an intermediate vertical supporting element (i.e. loss of load-carrying capacity in a critical element), leading to an increased span for composite floor slabs. In a lowrise building, if there is enough reinforcement throughout the slab and enough continuity and restraint, despite large deflections that will develop, the slab is capable of carrying the loads by membrane action. Fundamentally, the floor system behaves as an inverted dome structure with radial tensile forces and a compressive hoop stresses. This holds true at ambient temperature, yet a similar resisting mechanism forms during fire. Previous research and experimental work shows that fire performance of composite floor slabs can be used to reduce the fire Protection Requirement of the steel elements, i.e. the designer should take advantage of reserve capacity in the composite floor slab membrane action. The utilization of membrane action in the design of composite floor slabs has been used, to some extent, for mitigating collapse from single events (blast or fire only). Given that, often the initial blast is followed by a secondary fire event, this work investigates the system-level performance of low-rise damaged buildings subject to post-blast fires. The hypothesis is that, when incorporated in the design, low-rise buildings can withstand the post-blast fires through membrane action of composite floor slabs. Application of this concept, within a performance-based framework, can be used to avoid progressive collapse, or at the minimum increase fire resistance to allow for safe evacuation. This work investigates the design Requirements for beam sizes, fire Protection, concrete reinforcement and cover thickness to develop membrane action for a pre-defined fire resistance rating under cascading post-blast fires.Peer reviewe
-
Post-blast fire resistance of low-rise buildings through membrane action of composite floor slabs
2017Co-Authors: Haase Bryce, Elhami Khorasani Negar, Gernay ThomasAbstract:peer reviewedaudience: researcher, professional, studentSever fires in buildings can lead to local failures, instability, partial or total collapse of the structure. In majority of the times, fire is a secondary event, after blast or impact, while the building has experienced some damage. Examples of widely known events include the 1968 Ronan Point collapse in the UK, the 1995 Oklahoma City bombing, the World Trade Center Collapse in New York in 2001, the 2014 collapse of a building at New York’s Harlem neighborhood due to a gas explosion, and the recent 2015 collapse of a building at New York’s East Village also due to a gas explosion. The initial shock to the building can be conservatively modeled by removing an intermediate vertical supporting element (i.e. loss of load-carrying capacity in a critical element), leading to an increased span for composite floor slabs. In a lowrise building, if there is enough reinforcement throughout the slab and enough continuity and restraint, despite large deflections that will develop, the slab is capable of carrying the loads by membrane action. Fundamentally, the floor system behaves as an inverted dome structure with radial tensile forces and a compressive hoop stresses. This holds true at ambient temperature, yet a similar resisting mechanism forms during fire. Previous research and experimental work shows that fire performance of composite floor slabs can be used to reduce the fire Protection Requirement of the steel elements, i.e. the designer should take advantage of reserve capacity in the composite floor slab membrane action. The utilization of membrane action in the design of composite floor slabs has been used, to some extent, for mitigating collapse from single events (blast or fire only). Given that, often the initial blast is followed by a secondary fire event, this work investigates the system-level performance of low-rise damaged buildings subject to post-blast fires. The hypothesis is that, when incorporated in the design, low-rise buildings can withstand the post-blast fires through membrane action of composite floor slabs. Application of this concept, within a performance-based framework, can be used to avoid progressive collapse, or at the minimum increase fire resistance to allow for safe evacuation. This work investigates the design Requirements for beam sizes, fire Protection, concrete reinforcement and cover thickness to develop membrane action for a pre-defined fire resistance rating under cascading post-blast fires
Haase Bryce - One of the best experts on this subject based on the ideXlab platform.
-
Post-blast fire resistance of low-rise buildings through membrane action of composite floor slabs
2017Co-Authors: Haase Bryce, Elhami Khorasani Negar, Gernay ThomasAbstract:Sever fires in buildings can lead to local failures, instability, partial or total collapse of the structure. In majority of the times, fire is a secondary event, after blast or impact, while the building has experienced some damage. Examples of widely known events include the 1968 Ronan Point collapse in the UK, the 1995 Oklahoma City bombing, the World Trade Center Collapse in New York in 2001, the 2014 collapse of a building at New York’s Harlem neighborhood due to a gas explosion, and the recent 2015 collapse of a building at New York’s East Village also due to a gas explosion. The initial shock to the building can be conservatively modeled by removing an intermediate vertical supporting element (i.e. loss of load-carrying capacity in a critical element), leading to an increased span for composite floor slabs. In a lowrise building, if there is enough reinforcement throughout the slab and enough continuity and restraint, despite large deflections that will develop, the slab is capable of carrying the loads by membrane action. Fundamentally, the floor system behaves as an inverted dome structure with radial tensile forces and a compressive hoop stresses. This holds true at ambient temperature, yet a similar resisting mechanism forms during fire. Previous research and experimental work shows that fire performance of composite floor slabs can be used to reduce the fire Protection Requirement of the steel elements, i.e. the designer should take advantage of reserve capacity in the composite floor slab membrane action. The utilization of membrane action in the design of composite floor slabs has been used, to some extent, for mitigating collapse from single events (blast or fire only). Given that, often the initial blast is followed by a secondary fire event, this work investigates the system-level performance of low-rise damaged buildings subject to post-blast fires. The hypothesis is that, when incorporated in the design, low-rise buildings can withstand the post-blast fires through membrane action of composite floor slabs. Application of this concept, within a performance-based framework, can be used to avoid progressive collapse, or at the minimum increase fire resistance to allow for safe evacuation. This work investigates the design Requirements for beam sizes, fire Protection, concrete reinforcement and cover thickness to develop membrane action for a pre-defined fire resistance rating under cascading post-blast fires.Peer reviewe
-
Post-blast fire resistance of low-rise buildings through membrane action of composite floor slabs
2017Co-Authors: Haase Bryce, Elhami Khorasani Negar, Gernay ThomasAbstract:peer reviewedaudience: researcher, professional, studentSever fires in buildings can lead to local failures, instability, partial or total collapse of the structure. In majority of the times, fire is a secondary event, after blast or impact, while the building has experienced some damage. Examples of widely known events include the 1968 Ronan Point collapse in the UK, the 1995 Oklahoma City bombing, the World Trade Center Collapse in New York in 2001, the 2014 collapse of a building at New York’s Harlem neighborhood due to a gas explosion, and the recent 2015 collapse of a building at New York’s East Village also due to a gas explosion. The initial shock to the building can be conservatively modeled by removing an intermediate vertical supporting element (i.e. loss of load-carrying capacity in a critical element), leading to an increased span for composite floor slabs. In a lowrise building, if there is enough reinforcement throughout the slab and enough continuity and restraint, despite large deflections that will develop, the slab is capable of carrying the loads by membrane action. Fundamentally, the floor system behaves as an inverted dome structure with radial tensile forces and a compressive hoop stresses. This holds true at ambient temperature, yet a similar resisting mechanism forms during fire. Previous research and experimental work shows that fire performance of composite floor slabs can be used to reduce the fire Protection Requirement of the steel elements, i.e. the designer should take advantage of reserve capacity in the composite floor slab membrane action. The utilization of membrane action in the design of composite floor slabs has been used, to some extent, for mitigating collapse from single events (blast or fire only). Given that, often the initial blast is followed by a secondary fire event, this work investigates the system-level performance of low-rise damaged buildings subject to post-blast fires. The hypothesis is that, when incorporated in the design, low-rise buildings can withstand the post-blast fires through membrane action of composite floor slabs. Application of this concept, within a performance-based framework, can be used to avoid progressive collapse, or at the minimum increase fire resistance to allow for safe evacuation. This work investigates the design Requirements for beam sizes, fire Protection, concrete reinforcement and cover thickness to develop membrane action for a pre-defined fire resistance rating under cascading post-blast fires
Elhami Khorasani Negar - One of the best experts on this subject based on the ideXlab platform.
-
Post-blast fire resistance of low-rise buildings through membrane action of composite floor slabs
2017Co-Authors: Haase Bryce, Elhami Khorasani Negar, Gernay ThomasAbstract:Sever fires in buildings can lead to local failures, instability, partial or total collapse of the structure. In majority of the times, fire is a secondary event, after blast or impact, while the building has experienced some damage. Examples of widely known events include the 1968 Ronan Point collapse in the UK, the 1995 Oklahoma City bombing, the World Trade Center Collapse in New York in 2001, the 2014 collapse of a building at New York’s Harlem neighborhood due to a gas explosion, and the recent 2015 collapse of a building at New York’s East Village also due to a gas explosion. The initial shock to the building can be conservatively modeled by removing an intermediate vertical supporting element (i.e. loss of load-carrying capacity in a critical element), leading to an increased span for composite floor slabs. In a lowrise building, if there is enough reinforcement throughout the slab and enough continuity and restraint, despite large deflections that will develop, the slab is capable of carrying the loads by membrane action. Fundamentally, the floor system behaves as an inverted dome structure with radial tensile forces and a compressive hoop stresses. This holds true at ambient temperature, yet a similar resisting mechanism forms during fire. Previous research and experimental work shows that fire performance of composite floor slabs can be used to reduce the fire Protection Requirement of the steel elements, i.e. the designer should take advantage of reserve capacity in the composite floor slab membrane action. The utilization of membrane action in the design of composite floor slabs has been used, to some extent, for mitigating collapse from single events (blast or fire only). Given that, often the initial blast is followed by a secondary fire event, this work investigates the system-level performance of low-rise damaged buildings subject to post-blast fires. The hypothesis is that, when incorporated in the design, low-rise buildings can withstand the post-blast fires through membrane action of composite floor slabs. Application of this concept, within a performance-based framework, can be used to avoid progressive collapse, or at the minimum increase fire resistance to allow for safe evacuation. This work investigates the design Requirements for beam sizes, fire Protection, concrete reinforcement and cover thickness to develop membrane action for a pre-defined fire resistance rating under cascading post-blast fires.Peer reviewe
-
Post-blast fire resistance of low-rise buildings through membrane action of composite floor slabs
2017Co-Authors: Haase Bryce, Elhami Khorasani Negar, Gernay ThomasAbstract:peer reviewedaudience: researcher, professional, studentSever fires in buildings can lead to local failures, instability, partial or total collapse of the structure. In majority of the times, fire is a secondary event, after blast or impact, while the building has experienced some damage. Examples of widely known events include the 1968 Ronan Point collapse in the UK, the 1995 Oklahoma City bombing, the World Trade Center Collapse in New York in 2001, the 2014 collapse of a building at New York’s Harlem neighborhood due to a gas explosion, and the recent 2015 collapse of a building at New York’s East Village also due to a gas explosion. The initial shock to the building can be conservatively modeled by removing an intermediate vertical supporting element (i.e. loss of load-carrying capacity in a critical element), leading to an increased span for composite floor slabs. In a lowrise building, if there is enough reinforcement throughout the slab and enough continuity and restraint, despite large deflections that will develop, the slab is capable of carrying the loads by membrane action. Fundamentally, the floor system behaves as an inverted dome structure with radial tensile forces and a compressive hoop stresses. This holds true at ambient temperature, yet a similar resisting mechanism forms during fire. Previous research and experimental work shows that fire performance of composite floor slabs can be used to reduce the fire Protection Requirement of the steel elements, i.e. the designer should take advantage of reserve capacity in the composite floor slab membrane action. The utilization of membrane action in the design of composite floor slabs has been used, to some extent, for mitigating collapse from single events (blast or fire only). Given that, often the initial blast is followed by a secondary fire event, this work investigates the system-level performance of low-rise damaged buildings subject to post-blast fires. The hypothesis is that, when incorporated in the design, low-rise buildings can withstand the post-blast fires through membrane action of composite floor slabs. Application of this concept, within a performance-based framework, can be used to avoid progressive collapse, or at the minimum increase fire resistance to allow for safe evacuation. This work investigates the design Requirements for beam sizes, fire Protection, concrete reinforcement and cover thickness to develop membrane action for a pre-defined fire resistance rating under cascading post-blast fires
Zhi Ding - One of the best experts on this subject based on the ideXlab platform.
-
optimal transmission strategies for dynamic spectrum access in cognitive radio networks
IEEE Transactions on Mobile Computing, 2009Co-Authors: Senhua Huang, Zhi DingAbstract:Cognitive radio offers a promising technology to mitigate spectrum shortage in wireless communications. It enables secondary users (SUs) to opportunistically access low-occupancy primary spectral bands as long as their negative effect on the primary user (PU) access is constrained. This PU Protection Requirement is particularly challenging for multiple SUs over a wide geographical area. In this paper, we study the fundamental performance limit on the throughput of cognitive radio networks under the PU packet collision constraint. With perfect sensing, we develop an optimum spectrum access strategy under generic PU traffic patterns. Without perfect sensing, we quantify the impact of missed detection and false alarm, and propose a modified threshold-based spectrum access strategy that achieves close-to-optimal performance. Moreover, we develop and evaluate a distributed access scheme that enables multiple SUs to collectively protect the PU while adapting to behavioral changes in PU usage patterns. Our results provide useful insight on the trade-off between the Protection of the primary user and the throughput performance of cognitive radios.
Anh Tuan Hoang - One of the best experts on this subject based on the ideXlab platform.
-
joint power control and beamforming for cognitive radio networks
IEEE Transactions on Wireless Communications, 2008Co-Authors: Habibul Islam, Yingchang Liang, Anh Tuan HoangAbstract:We consider a secondary usage of spectrum scenario where a secondary network coexists and/or shares the radio spectrum with a primary network to which the spectrum is licensed. The secondary network uses cognitive radio technology to make opportunistic access of the unused and/or underutilized portions of the spectrum. For such a system, we study the problem of joint power control and beamforming with the objective of minimizing the total transmitted power of the cognitive network such that the received interferences at primary users remain below a threshold level as well as the secondary users who are admitted in the system are guaranteed with their signal to interference plus noise ratio (SINR) Requirements. Two iterative algorithms, one based on weighted least square (WLS) approach and the other based on admission control for secondary users, are provided to meet the strict interference Protection Requirement of the primary users. A numerical study is performed to show the convergence behavior of the iterative algorithms.
