Retrofitting of Single Unit Tunnel Form Building Using Steel Plate under Out-of-Plane Lateral Cyclic Loading

2014 ◽  
Vol 661 ◽  
pp. 95-99 ◽  
Author(s):  
Shamilah Anudai Anuar ◽  
Nor Hayati Hamid ◽  
M.H. Hashim
Keyword(s):  
Cyclic Loading ◽  
Single Unit ◽  
Steel Plate ◽  
Hysteresis Loops ◽  
Seismic Loading ◽  
Visual Observation ◽  
Equivalent Viscous Damping ◽  
Before And After ◽  
Out Of Plane ◽  
Lateral Strength

A one-third scale single unit of 3-storey tunnel form building with foundation beam was designed, constructed and tested under out-of-plane lateral cyclic loading. This building was designed according to BS8110 with no provision for seismic loading. Tunnel form building was initially tested at ±0.01% , ±0.1%, ±0.25%, ±0.5%, ±0.75%, ±1.00%, ±1.25% and ±1.5% drifts until the structure lost its lateral strength (strength degradation). Then, the specimen was repaired and retrofitted using steel plate and angle which was positioned at the wall-slab joints that had suffered severe damages. A similar drift of displacement before retrofitting was repeated for the specimen after being retrofitted. Visual observation of damages, hysteresis loops, stiffness, ductility and equivalent viscous damping (EVD) of the specimen were analyzed and compared before and after retrofitting. The proposed retrofitting technique has increased its lateral strength by 26%. Fewer cracks occurred after retrofitting the specimen compared to before retrofitting. It can be concluded that steel plate and angle can strengthen the wall-slab joint and this method can be used to retrofit the tunnel form building if it had been damaged caused by earthquake excitations.

Retrofitting of a Double Unit Tunnel Form Building Using Additional RC Wall, Steel Angle and CFRP

2014 ◽  
Vol 661 ◽  
pp. 123-127 ◽  
Author(s):  
Nor Hayati Hamid ◽  
S.H. Anuar ◽  
N.L. Azmi
Keyword(s):  
Cyclic Loading ◽  
Low Cost ◽  
Seismic Retrofitting ◽  
Fiber Reinforced Polymer ◽  
Viscous Damping ◽  
Equivalent Viscous Damping ◽  
Reinforced Polymer ◽  
Steel Angle ◽  
Before And After ◽  
Lateral Strength

Tunnel form construction is widely known as modern construction method that enables the construction of horizontal and vertical elements simultaneously. It is quickly construct low cost, high quality and earthquake safe to construct cellular buildings. Main objective of this study is to determine the seismic retrofitting performance of a double unit tunnel form building when retrofitted using additional RC wall, steel angle and Carbon Fiber Reinforced Polymer (CFRP) when tested under in-plane lateral cyclic loading. A comparison of tunnel form building was made before and after retrofitting in terms of lateral strength, stiffness, ductility and equivalent viscous damping. Result indicates that retrofitting method using additional RC wall, steel angle and CFRP was able to increase the lateral strength, ductility and equivalent viscous damping under in-plane lateral cyclic loading. The result also shows the effectiveness of additional RC wall, steel angle and CFRP in improving the shear resistances and deformation capacities of concrete structures and delaying their stiffness degradation under earthquake loading.

Comparison of Seismic Performance between Single and Double Unit Tunnel Form Building under In-Plane Lateral Cyclic Loading

2014 ◽  
Vol 567 ◽  
pp. 687-692 ◽  
Author(s):  
Shamilah Anudai Anuar ◽  
Nor Hayati Abdul Hamid
Keyword(s):  
Cyclic Loading ◽  
Seismic Performance ◽  
Experimental Work ◽  
Single Unit ◽  
Viscous Damping ◽  
Equivalent Viscous Damping ◽  
Significant Percentage ◽  
Percentage Difference ◽  
Strength Capacity ◽  
Lateral Strength

This paper summarizes the comparison of seismic performance between single and double unit tunnel form building (TFB) under in-plane lateral cyclic loading. Experimental work was carried out to determine the lateral strength capacity, stiffness, ductility, and equivalent viscous damping (EVD) for both specimens. The comparisons of these parameters for both specimens were made to determine its percentage difference. The maximum lateral strength capacity obtained from single unit TFB with 8.68% higher than double unit TFB. As for stiffness behaviour, single unit was found to be much more stiffened compared to double unit. The EVD value showed that single unit absorbed much more energy compared to double unit of TFB. However, double unit TFB indicated a significant percentage of increment compared to the single unit TFB. Therefore, double unit TFB is safer to be built compared to single unit especially for seismic regions.

Comparison of Seismic Behaviour for a Single Unit Tunnel Form RC Building before and after Repaired

2014 ◽  
Vol 905 ◽  
pp. 254-258 ◽  
Author(s):  
S.A. Anuar ◽  
Nor Hayati Hamid ◽  
M.H. Hashim
Keyword(s):  
Near Field ◽  
Combination Method ◽  
Seismic Behaviour ◽  
Equivalent Viscous Damping ◽  
Code Of Practice ◽  
Carbon Fiber Reinforce Polymer ◽  
Strength Capacity ◽  
Before And After ◽  
Lateral Strength ◽  
Angle Steel

Repairing and strengthening the structures are gaining more attention from many researchers and structural engineers after the structures suffered damages from natural disasters. Tunnel form RC buildings which are not designed according to seismic code of practice are very vulnerable to ground motion when located to near field earthquake. This paper presents the method of repair and strengthening of 3-storey tunnel form building subjected to in-plane lateral cyclic loading. The building was strengthened using the combination method of steel angle, steel plate and Carbon Fiber Reinforce Polymer (CFRP) sheet. The results show that the lateral strength capacity is increase by 15.66%, ductility increase by 53.57% and equivalent viscous damping increase by 28.88% for the first cycle and 33.65% for the second cycle. However, the stiffness of the structure reduce by 56.6%. It can be concluded that this method can be adopted for the damage of tunnel form building system.

Novel Electro Polymerization Method to Synthesized Anti-corrosion Coated Layer on Stainless Steel Surface from (N-Benzothiazolyl Maleamic Acid) and Study its Biological Activity

2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Muna I Khalaf ◽  
Khulood A Saleh ◽  
Khalil S Khalil
Keyword(s):  
Stainless Steel ◽  
Chemical Structure ◽  
Inhibition Efficiency ◽  
Steel Plate ◽  
Polymeric Coating ◽  
Stainless Steel Surface ◽  
Plate Electrode ◽  
Before And After ◽  
Maleamic Acid ◽  
Polymerization Method

Electro polymerization of N-benzothiazolyl maleamic acid (NBM) was carried out on stainless steel plate electrode in a protic medium of monomer aqueous solution using electrochemical oxidation procedure in electrochemical cell.Spectroscopic characterization techniques were investigated to obtain information about the chemical structure of polymer. The anti-corrosion action of polymer was investigated on stainless steel by electrochemical polarization method. In addition, the effect of adding nanomaterial (TiO2, ZnO (bulk-nano)) to monomer solution on the corrosion behavior of stainless steel was investigated. The results obtained showed that the corrosion rate of S-steel increased with temperature increase from 293K to 323K and the values of inhibition efficiency by coating polymer increase with nanomaterial addition. Apparent energies of activation have been calculated for the corrosion process of S-steel in acidic medium before and after polymeric coating. Furthermore were studied the effect of the preparing polymer on some strain of bacteria.

Sources of the Scalp-Recorded Amplitude-Modulation Following Response

2002 ◽  
Vol 13 (04) ◽  
pp. 188-204 ◽  
Author(s):  
Shigeyuki Kuwada ◽  
Julia S. Anderson ◽  
Ranjan Batra ◽  
Douglas C. Fitzpatrick ◽  
Natacha Teissier ◽  
...  
Keyword(s):  
Animal Model ◽  
Amplitude Modulation ◽  
Single Unit ◽  
Modulation Frequency ◽  
Multiple Sources ◽  
High Modulation ◽  
Before And After ◽  
Single Unit Recordings ◽  
Composite Response ◽  
The Brain

The scalp-recorded amplitude-modulation following response (AMFR)” is gaining recognition as an objective audiometric tool, but little is known about the neural sources that underlie this potential. We hypothesized, based on our human studies and single-unit recordings in animals, that the scalp-recorded AMFR reflects the interaction of multiple sources. We tested this hypothesis using an animal model, the unanesthetized rabbit. We compared AMFRs recorded from the surface of the brain at different locations and before and after the administration of agents likely to enhance or suppress neural generators. We also recorded AMFRs locally at several stations along the auditory neuraxis. We conclude that the surface-recorded AMFR is indeed a composite response from multiple brain generators. Although the response at any modulation frequency can reflect the activity of more than one generator, the AMFRs to low and high modulation frequencies appear to reflect a strong contribution from cortical and subcortical sources, respectively.

Fatigue of Steel Plate Panels due to Repeated Out-of-plane Deflection under Cyclic Loads

2004 ◽  
Vol 88 (6) ◽  
pp. 397-402
Author(s):  
Duncan Paterson ◽  
Ben T. Yen ◽  
John W. Fisher
Keyword(s):  
Steel Plate ◽  
Cyclic Loads ◽  
Out Of Plane ◽  
Plate Panels

Effects of Dynamic Strain-Aging and Cyclic Loading on Fracture Behavior of Ferritic Steels

2002 ◽  
Author(s):  
K. Linga Murty ◽  
Chang-Sung Seok
Keyword(s):  
Fracture Toughness ◽  
Cyclic Loading ◽  
Strain Aging ◽  
Crack Tip ◽  
Load Ratio ◽  
Seismic Loading ◽  
Dynamic Strain ◽  
Ferritic Steels ◽  
Bend Tests ◽  
Point Bend

Ferritic steels commonly used for pressure vessels and reactor supports in light water reactors (LWRs) exhibit dynamic strain aging (DSA) resulting in decreased ductility and toughness. In addition, recent work indicated decreased toughness during reverse-cyclic loading that has implications on reliability of these structures under seismic loading conditions. We summarize some of our recent work on these aspects along with synergistic effects, of interstitial impurity atoms (IIAs) and radiation induced point defects, that result in interesting beneficial effects of radiation exposure at appropriate temperature and strain-rate conditions. Radiation-defect interactions were investigated on pure iron, Si-killed mild steel, A533B, A516, A588 and other reactor support and vessel steels. In all cases, DSA is seen to result in decreased ductility accompanied by increased work-hardening parameter. In addition to mechanical property tests, fracture toughness is investigated on both A533B and A516 steels. While dips in fracture toughness are observed in A533B steel in the DSA region, A516 steel exhibited at best a plateau. The reasons could lie in the applied strain-rates; while J1c tests were performed on A533B steel using 3-point bend tests on Charpy type specimens, CT specimens were used for A516 steel. However, tensile and 3-point bend tests on similar grade A516 steel of different vintage did exhibit distinct drop in the energy to fracture. Load-displacement curves during J1c tests on CT specimens did show load drops in the DSA regime. The effect of load ratio (R) on J versus load-line displacement curves for A516 steel is investigated from +1 to −1 at a fixed normalized incremental plastic displacement of 0.1 (R = 1 corresponds to monotonic loading). We note that J-values are significantly reduced with decreasing load ratio. The work-hardening characteristics on the fracture surfaces were studied following monotonic and cyclic loading fracture tests along with the stress-field analyses. From the hardness and the ball-indentation tests, it was shown that decreased load ratio (R) leads to more strain hardening at the crack tip resulting in decreased fracture toughness. From the stress field analysis near the crack tip of a compact tension fracture toughness test specimen, a cycle of tensile and compressive loads is seen to result in tensile residual stresses (which did not exist at the crack tip before). These results are important to evaluations of flawed-structures under seismic loading conditions, i.e. Leak-Before-Break (LBB) and in-service flaw evaluation criteria where seismic loading is addressed. In addition, studies on fast vs total (thermal+fast) neutron spectra revealed unexpected results due to the influence of radiation exposure on source hardening component of the yield stress; grain-size of pure iron plays a significant role in these effects.

Using the Simplified 3D DIC Method to Measure the Deformation of 3D Surface

2011 ◽  
Vol 121-126 ◽  
pp. 3945-3949 ◽  
Author(s):  
Shih Heng Tung ◽  
Jui Chao Kuo ◽  
Ming Hsiang Shih ◽  
Wen Pei Sung
Keyword(s):  
Measurement Accuracy ◽  
Good Accuracy ◽  
Correlation Method ◽  
Image Correlation ◽  
2D Digital Image Correlation ◽  
Plate Specimen ◽  
Before And After ◽  
Out Of Plane ◽  
Plane Displacement ◽  
2D And 3D

In recent years, 2D digital image correlation method (DIC) has been widely used in the measurement of plane strain. However, out-of-plane displacement could be induced during the loading and it would affect the measurement accuracy. Thus, a 3D measurement is necessary. This study utilizes a simplified 3D DIC to measure the geometry of an object before and after deformation. Then the finite element concept is involved to determine the strain after deformation. A flat plate specimen with in-plane and out-of-plane displacement is observed. Both 2D and 3D DIC are used to analyze the strain. The results show that using 3D DIC to measure strain is feasible and with a very good accuracy.

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