Experimental Investigations of RC Frames Retrofitted by Steel Braced Frames Using a New Hybrid Connection

2011 ◽  
Vol 82 ◽  
pp. 594-599
Author(s):  
Misato Nishiyama ◽  
Pasha Javadi ◽  
Koki Maeda ◽  
Tetsuo Yamakawa
Keyword(s):  
Fundamental Mode ◽  
Shear Failure ◽  
High Strength ◽  
Steel Plates ◽  
Flexural Behavior ◽  
Experimental Investigations ◽  
Type I ◽  
Rc Frame ◽  
Type Ii ◽  
Direct Shear

In this paper, a new connection technique for installing steel braced frame inside an existing RC frame is proposed. The proposed connection, which is called “Hybrid Connection”, consists of high-strength grout, steel plates and high-strength bolts. In the current investigation, two fundamental modes, namely, Type I and Type II are experimentally verified. In the fundamental mode of Type I, the steel braces buckle and stretch, and the RC frame and the steel frame exhibit flexural behavior. In the fundamental mode of Type II, direct-shear failure happens in the hybrid connection at the beam connection, and punching (direct-shear) failure occurs at the top of RC columns.

scholarly journals Screw head plugs increase the fatigue strength of stainless steel, but not of titanium, locking plates

2018 ◽  
Vol 7 (12) ◽  
pp. 629-635 ◽  
Author(s):  
L-W. Hung ◽  
C-K. Chao ◽  
J-R. Huang ◽  
J. Lin
Keyword(s):  
Stainless Steel ◽  
Fatigue Strength ◽  
Steel Plates ◽  
Bending Test ◽  
Type I ◽  
Locking Plates ◽  
Type Ii ◽  
Screw Head ◽  
Type Iii ◽  
Four Point Bending

ObjectivesScrew plugs have been reported to increase the fatigue strength of stainless steel locking plates. The objective of this study was to examine and compare this effect between stainless steel and titanium locking plates.MethodsCustom-designed locking plates with identical structures were fabricated from stainless steel and a titanium alloy. Three types of plates were compared: type I unplugged plates; type II plugged plates with a 4 Nm torque; and type III plugged plates with a 12 Nm torque. The stiffness, yield strength, and fatigue strength of the plates were investigated through a four-point bending test. Failure analyses were performed subsequently.ResultsFor stainless steel, type II and type III plates had significantly higher fatigue strength than type I plates. For titanium, there were no significant differences between the fatigue strengths of the three types of plates. Failure analyses showed local plastic deformations at the threads of screw plugs in type II and type III stainless steel plates but not in titanium plates.ConclusionThe screw plugs could increase the fatigue strength of stainless steel plates but not of titanium plates. Therefore, leaving screw holes open around fracture sites is recommended in titanium plates. Cite this article: L-W. Hung, C-K. Chao, J-R. Huang, J. Lin. Screw head plugs increase the fatigue strength of stainless steel, but not of titanium, locking plates. Bone Joint Res 2018;7:629–635. DOI: 10.1302/2046-3758.712.BJR-2018-0083.R1.

Vibration Characteristics of Al6061-SiC Metal Matrix Composite based Rubber Mount for I.C Engine Chassis

2018 ◽  
Vol 10 (3) ◽  
Author(s):  
T. Ramachandran ◽  
S. Sudhakara Reddy ◽  
S. Jeyakumar
Keyword(s):  
Metal Matrix ◽  
Vibration Isolation ◽  
Dynamic Properties ◽  
Engineering Application ◽  
Weight Ratio ◽  
High Strength ◽  
Steel Plates ◽  
Experimental Investigations ◽  
Matrix Composites ◽  
Engine Mount

Vibrations are found to be dangerous and reduce the life and reliability of the vehicle. The studies were carried out by many researchers to stiff the structures by increasing the wall thickness of the plates, rubber and to minimize the vibration by increasing the damping coefficient of the rubber materials. The conventional materials indicate an improvement in stiffness, but not satisfying the requirements of the engine vibration at different speed and load standards and also increased the mass of the structure. This research on the engine mount vibration isolation aims at developing an alternative material for the structures which exhibit good damping and stiffness characteristics. In terms of properties such as chemical resistance, ease of production, high strength to weight ratio and damping, composite materials are increasingly used in many engineering application where the vibration is predominant. In this paper, the steel plates are replaced by Al6061-SiC Metal Matrix Composites (MMC) and studies are carried out on the engine mount made of Al6061 MMC structural material and integrated with rubber. The static and dynamic properties of the Al6061MMC-rubber mounts are determined using experimental investigations. The harmonic analysis is also carried out to test the damping characteristics of the mounts.

Experimental Investigation on Soft-Story RC Frames Retrofitted by Hybrid Wall Technique

2011 ◽  
Vol 82 ◽  
pp. 612-617
Author(s):  
Tomomi Sunagawa ◽  
Pasha Javadi ◽  
Koki Maeda ◽  
Tetsuo Yamakawa
Keyword(s):  
Experimental Investigation ◽  
High Strength ◽  
Steel Plates ◽  
Structural Performance ◽  
Experimental Investigations ◽  
Rc Columns ◽  
Soft Story ◽  
Rc Frames ◽  
Hybrid Walls

In this paper, a new retrofit method, which is called “Hybrid Wall Technique”, is proposed for retrofitting soft-story RC frames. In the proposed technique, steel plates encase the boundary RC columns, and connect to additional steel plates at the bay of the frame with the help of high-strength bolts. After installation of steel plates and high-strength bolts, which are also used as formworks, the additional concrete is cast. Structural performance of the proposed metho­­­d is verified by experimental investigations conducted on one-bay one-story RC frames. One non-retrofitted frame and three frames retrofitted by thick or thin hybrid walls were evaluated experimentally.

scholarly journals Behavior of reinforced high and ultra high strength concrete beams

2021 ◽  
Author(s):  
Shahid Mohammad. Neaz
Keyword(s):  
High Strength Concrete ◽  
Shear Failure ◽  
Load Capacity ◽  
Single Point ◽  
High Strength ◽  
Experimental Investigations ◽  
Type B ◽  
Initial Stiffness ◽  
Strength Concrete ◽  
Reinforced Beams

Load-deflection behaviour of reinforced beams with high strength concrete (HSC) and ultra high strength concrete (UHSC) were studied based on experimental investigations. Four concretes including one HSC and three UHSC were considered for construction of beam specimens. Two different cross-sections of reinforced beams namely Type A and Type B were considered for testing under single point loading. In addition, three sets of Type B beam were tested with three different shear span to depth ratio (a/d) for each concrete mix. The test results confirmed that flexural strength of fibre reinforced concrete increases with the increase of compressive strength of concrete and the initial stiffness of UHSC are very high compared to HSC. It was observed that Type B beam with a/d ratio less than 2 show the pattern of shear failure. As such, a theoretical model was studied to verify the performance and the shear load capacity of beams.

scholarly journals Behavior of reinforced high and ultra high strength concrete beams

2021 ◽  
Author(s):  
Shahid Mohammad. Neaz
Keyword(s):  
High Strength Concrete ◽  
Shear Failure ◽  
Load Capacity ◽  
Single Point ◽  
High Strength ◽  
Experimental Investigations ◽  
Type B ◽  
Initial Stiffness ◽  
Strength Concrete ◽  
Reinforced Beams

Load-deflection behaviour of reinforced beams with high strength concrete (HSC) and ultra high strength concrete (UHSC) were studied based on experimental investigations. Four concretes including one HSC and three UHSC were considered for construction of beam specimens. Two different cross-sections of reinforced beams namely Type A and Type B were considered for testing under single point loading. In addition, three sets of Type B beam were tested with three different shear span to depth ratio (a/d) for each concrete mix. The test results confirmed that flexural strength of fibre reinforced concrete increases with the increase of compressive strength of concrete and the initial stiffness of UHSC are very high compared to HSC. It was observed that Type B beam with a/d ratio less than 2 show the pattern of shear failure. As such, a theoretical model was studied to verify the performance and the shear load capacity of beams.

scholarly journals Experimental Study on Novel Energy-Dissipating Prefabricated Beam-Column Joints

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Qiong Liu ◽  
Shanghong Chen ◽  
Wei Lin ◽  
Fanjin Zeng
Keyword(s):  
Shear Failure ◽  
Structural Integrity ◽  
Plastic Hinge ◽  
High Strength ◽  
Internal Force ◽  
Steel Plates ◽  
Engineering Structures ◽  
Anchor System ◽  
Steel Bar ◽  
New Type

A new dapped-end beam to column connection is designed in this paper. Its assembly connection zone changes from inside the joint to midspan of the beam. The proposed connection can not only provide good structural integrity but also ensure that the plastic hinge moves away from the column edge. The rotational capacity of the plastic hinge determines the internal force redistribution of the joint and the energy dissipation capacity. The high-strength bolts and steel plates are used to realize connection, further enhancing the rotation of the plastic hinge and minimizing the cast-in-place concrete volume. Three full-scale exterior beam to column joints are casted and then subjected to reversal cyclic loading. The finite element (FE) analyses are carried out to compare with experimental results and study the effect of connection position on the structural behaviours. The obtained results show that the plastic hinges of all three specimens are firstly developed to a distance from the column edge, thus revealing that this kind of joint can achieve beam hinge mechanism and prevent joint shear failure. And the connection position is the most disadvantaged when coinciding with the plastic hinge zone, which would result in the excessive deformation and the early failure of the steel bar anchor system. The new type of joint shows good seismic performance during earthquake if the connection can be properly designed, and thus this kind of structural form can be applied to actual engineering structures in seismic regions.

Heat-Etching with a Bullivant Type II Simple Freeze-Cleave Device

1970 ◽  
Vol 28 ◽  
pp. 106-107 ◽  
Author(s):  
Ronald S. Weinstein ◽  
N. Scott McNutt
Keyword(s):  
New Zealand ◽  
General Hospital ◽  
Massachusetts General Hospital ◽  
Type I ◽  
Type Ii ◽  
Collaborative Effort ◽  
Temperature And Pressure ◽  
The University

The Type I simple cold block device was described by Bullivant and Ames in 1966 and represented the product of the first successful effort to simplify the equipment required to do sophisticated freeze-cleave techniques. Bullivant, Weinstein and Someda described the Type II device which is a modification of the Type I device and was developed as a collaborative effort at the Massachusetts General Hospital and the University of Auckland, New Zealand. The modifications reduced specimen contamination and provided controlled specimen warming for heat-etching of fracture faces. We have now tested the Mass. General Hospital version of the Type II device (called the “Type II-MGH device”) on a wide variety of biological specimens and have established temperature and pressure curves for routine heat-etching with the device.

Labelling of non-A, non-B hepatitis infected chimpanzee hepatocytes with nuclease-gold conjugates

1984 ◽  
Vol 42 ◽  
pp. 250-251
Author(s):  
G. D. Gagne ◽  
M. F. Miller ◽  
D. A. Peterson
Keyword(s):  
Endoplasmic Reticulum ◽  
Experimental Infection ◽  
Uranyl Acetate ◽  
Type I ◽  
Cellular Injury ◽  
Type Ii ◽  
Tubular Structures ◽  
Type Iii ◽  
Type Iv ◽  
Infected Chimpanzee

Experimental infection of chimpanzees with non-A, non-B hepatitis (NANB) or with delta agent hepatitis results in the appearance of characteristic cytoplasmic alterations in the hepatocytes. These alterations include spongelike inclusions (Type I), attached convoluted membranes (Type II), tubular structures (Type III), and microtubular aggregates (Type IV) (Fig. 1). Type I, II and III structures are, by association, believed to be derived from endoplasmic reticulum and may be morphogenetically related. Type IV structures are generally observed free in the cytoplasm but sometimes in the vicinity of type III structures. It is not known whether these structures are somehow involved in the replication and/or assembly of the putative NANB virus or whether they are simply nonspecific responses to cellular injury. When treated with uranyl acetate, type I, II and III structures stain intensely as if they might contain nucleic acids. If these structures do correspond to intermediates in the replication of a virus, one might expect them to contain DNA or RNA and the present study was undertaken to explore this possibility.

Comparative surface and ultrastructural views of methylotrophic bacteria by TEM, STEM, SE, and freeze-etch electron microscopy.

1987 ◽  
Vol 45 ◽  
pp. 792-793
Author(s):  
T.A. Fassel ◽  
M.J. Schaller ◽  
M.E. Lidstrom ◽  
C.C. Remsen
Keyword(s):  
Cytoplasmic Membrane ◽  
Structural Features ◽  
Methylotrophic Bacteria ◽  
Type I ◽  
Type Ii ◽  
Membrane Complex ◽  
Oxidation Of Methane ◽  
Methane Oxidizing Bacteria ◽  
Wall Structures ◽  
Methylomonas Albus

Methylotrophic bacteria play an Important role in the environment in the oxidation of methane and methanol. Extensive intracytoplasmic membranes (ICM) have been associated with the oxidation processes in methylotrophs and chemolithotrophic bacteria. Classification on the basis of ICM arrangement distinguishes 2 types of methylotrophs. Bundles or vesicular stacks of ICM located away from the cytoplasmic membrane and extending into the cytoplasm are present in Type I methylotrophs. In Type II methylotrophs, the ICM form pairs of peripheral membranes located parallel to the cytoplasmic membrane. Complex cell wall structures of tightly packed cup-shaped subunits have been described in strains of marine and freshwater phototrophic sulfur bacteria and several strains of methane oxidizing bacteria. We examined the ultrastructure of the methylotrophs with particular view of the ICM and surface structural features, between representatives of the Type I Methylomonas albus (BG8), and Type II Methylosinus trichosporium (OB-36).

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