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Full-Text Articles in Engineering
Dynamic Compressive Properties Of Heat-Treated And Pre-Stressed Cement Mortar Specimen Subjected To Cyclic Impact Loading, Ronghua Shu, Guang Xu, Lijinhong Huang
Dynamic Compressive Properties Of Heat-Treated And Pre-Stressed Cement Mortar Specimen Subjected To Cyclic Impact Loading, Ronghua Shu, Guang Xu, Lijinhong Huang
Mining Engineering Faculty Research & Creative Works
By carrying out the cyclic dynamic compressive experiment, the dynamic compressive properties of heat-treated and pre-stressed cement mortar subjected to cyclic impact loading were obtained. The results show that under static and cyclic impact loading, the peak stress shows a nonlinear decrease trend with the increasing dynamic impact number, and the failure strength decreases as heated temperature increases. The strain rate shows a linear increase trend as impact number increases. The relationship among the strain rate, temperature and impact number obey exponential relations, which could be expressed as ε˙ = 0.64E0.00854T+4.93 X 10−3tn+0.77N+18.70. The strain rate increase factor could be …
Numerical And Experimental Investigation Of Negative Stiffness Beams And Honeycomb Structures, Yasser Darwish, Mohamed A. Elgawady
Numerical And Experimental Investigation Of Negative Stiffness Beams And Honeycomb Structures, Yasser Darwish, Mohamed A. Elgawady
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Metamaterial structures that exhibit negative stiffness (MSNS) behavior have shown the potential to be used as energy dissipation systems in different applications. Negative stiffness honeycomb structures consist of multiple pre-buckled beams that snapping through from one pre-buckled mode to another buckled mode, when subjected to transverse loads, displaying negative stiffness, and dissipating a significant portion of the input energy. This paper presents finite element models (FEMs) developed to investigate the performance of negative stiffness pre-buckled beams and honeycombs. The FEMs were validated using experimental results of single pre-buckled beams and honeycomb structures. The experimental testing of the pre-buckled beams was …
Performance Of Smart Shear Keys In Concrete Bridges Under Tsunami Loading: An Experimental Study, Haibin Zhang, Xinzhe Yuan, Genda Chen, Pedro Lomonaco
Performance Of Smart Shear Keys In Concrete Bridges Under Tsunami Loading: An Experimental Study, Haibin Zhang, Xinzhe Yuan, Genda Chen, Pedro Lomonaco
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Bridges have recently been exposed to an increasing number of natural hazards such as earthquakes and tsunamis. These extreme events have resulted in transverse offsets, overturning moments, and even dropping-off of superstructures due to their weak connection to substructures. These outcomes are potentially prevented or mitigated by developing and deploying sliding, modular, adaptive, replaceable, and two-dimensional (SMART) shear keys as fuse elements between superstructures and substructures. The novelty of SMART shear keys is to enable an adaptive control of both the force and displacement of bridges under different types of loads. In this study, the performance of SMART shear keys …
Focus Energy Determination Of Mining Microseisms Using Residual Seismic Wave Attenuation In Deep Coal Mining, Mingwei Zhang, Shengdong Liu, Shuzhao Chen, Yanlong Chen, Guang Xu, Deyu Qian
Focus Energy Determination Of Mining Microseisms Using Residual Seismic Wave Attenuation In Deep Coal Mining, Mingwei Zhang, Shengdong Liu, Shuzhao Chen, Yanlong Chen, Guang Xu, Deyu Qian
Mining Engineering Faculty Research & Creative Works
Based on the energy attenuation characteristics of residual wave in deep rock, a method was developed to determine the microseismic focus energy. Differential energy loss in infinitesimal spreading distance is logically deduced, upon which energy attenuation equation was established. With a logarithmic transformation, a linear relation of the residual seismic energy with distance is formulated. Its intercept was used to determine the microseismic focus energy. The result is compared with that determined by the energy density method. The reliability of the determined focus energy and the impact of the built-in velocity threshold on the residual wave energy computation are discussed. …
Seismic Performance Of Hollow-Core Composite Columns Under Cyclic Loading, Mohanad M. Abdulazeez, Mohamed Elgawady
Seismic Performance Of Hollow-Core Composite Columns Under Cyclic Loading, Mohanad M. Abdulazeez, Mohamed Elgawady
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This paper experimentally investigates the seismic behavior of a large-scale, hollow-core, fiber-reinforced, polymerconcrete- steel HC-FCS column under cyclic loading. The typical precast HC-FCS member consists of a concrete wall sandwiched between an outer fiber-reinforced polymer (FRP) tube and an inner steel tube. The FRP tube provides continuous confinement for the concrete wall, along the height of the column. The column is inserted into the footing and temporarily supported; then, the footing is cast in place around the column. The seismic performance of the precast HC-FCS columns was assessed and compared with previous experimental work. The compared column had the same …
Multi-Objective Dynamic Economic Dispatch With Demand Side Management Of Residential Loads And Electric Vehicles, Mohammad Rasoul Narimani, Fnu Maigha, Jhi-Young Joo, Mariesa Crow
Multi-Objective Dynamic Economic Dispatch With Demand Side Management Of Residential Loads And Electric Vehicles, Mohammad Rasoul Narimani, Fnu Maigha, Jhi-Young Joo, Mariesa Crow
Electrical and Computer Engineering Faculty Research & Creative Works
In this paper, a multi-objective optimization method based on the normal boundary intersection is proposed to solve the dynamic economic dispatch with demand side management of individual residential loads and electric vehicles. The proposed approach specifically addresses consumer comfort through acceptable appliance deferral times and electric vehicle charging requirements. The multi-objectives of minimizing generation costs, emissions, and energy loss in the system are balanced in a Pareto front approach in which a fuzzy decision making method has been implemented to find the best compromise solution based on desired system operating conditions. The normal boundary intersection method is described and validated.
Behavior And Fatigue Properties Of Metallic Dampers For Seismic Retrofit Of Highway Bridges, Genda Chen, Stephen Eads
Behavior And Fatigue Properties Of Metallic Dampers For Seismic Retrofit Of Highway Bridges, Genda Chen, Stephen Eads
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The objective of this study is to develop an economical solution with metallic dampers for the seismic retrofit of highway bridges in low occurrence seismic zones, such as in the Central and Eastern United States. Select low carbon steel rods were first tested for their ductile behavior and material strength. Large-scale, tapered rods were then tested for their energy dissipation capability and fatigue strength under regular, irregular, and earthquake loads. A full-scale damper made of five tapered rods was designed next for the seismic retrofit of a three-span continuous steel-girder bridge in southeast Missouri; its system performance including joints and …