Behaviour of Grout-Filled Splice under Monotonic and Cyclic Loads

2014 ◽  
Vol 1079-1080 ◽  
pp. 322-326
Author(s):  
Yong Feng Zheng ◽  
Zheng Xing Guo ◽  
Ming Xie
Keyword(s):  
Tensile Strength ◽  
Great Influence ◽  
Compressive Load ◽  
Tensile Load ◽  
Construction Market ◽  
Splice System ◽  
Cavity Configuration ◽  
New Type ◽  
Precast Construction ◽  
Seamless Steel

Grout-filled mechanical splice system is one of the most important technologies for precast construction. However, due to the high cost of grouted sleeve in Chinese construction market, the implementation of this technology is hindered. In this study, a new type of grouted sleeve was developed with standard seamless steel pipe by cold rolling depression. Utilizing this sleeve, eight coupler specimens were prepared and tested under incremental tensile load and cyclic load. The results indicate that all the specimens provided satisfactory behaviour of which the ultimate tensile strength exceeded the required loading capacity specified in ACI318 and JGJ107. The inner cavity configuration of the grouted sleeve has great influence on the confining mechanism of the splice and on the strain distribution in the sleeve. Because the compressive strength of grout is greatly higher than its tensile strength, the slope of the load-strain response curve of the sleeve under tensile load is lower than it under compressive load.

Vibratory weld conditioning during gas tungsten arc welding of al 5052 alloy on the mechanical and micro-structural behavior

2020 ◽  
Vol 17 (6) ◽  
pp. 831-836
Author(s):  
M. Vykunta Rao ◽  
Srinivasa Rao P. ◽  
B. Surendra Babu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welded Joints ◽  
Great Influence ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Content Type ◽  
Average Grain Size

Purpose Vibratory weld conditioning parameters have a great influence on the improvement of mechanical properties of weld connections. The purpose of this paper is to understand the influence of vibratory weld conditioning on the mechanical and microstructural characterization of aluminum 5052 alloy weldments. An attempt is made to understand the effect of the vibratory tungsten inert gas (TIG) welding process parameters on the hardness, ultimate tensile strength and microstructure of Al 5052-H32 alloy weldments. Design/methodology/approach Aluminum 5052 H32 specimens are welded at different combinations of vibromotor voltage inputs and time of vibrations. Voltage input is varied from 50 to 230 V at an interval of 10 V. At each voltage input to the vibromotor, there are three levels of time of vibration, i.e. 80, 90 and 100 s. The vibratory TIG-welded specimens are tested for their mechanical and microstructural properties. Findings The results indicate that the mechanical properties of aluminum alloy weld connections improved by increasing voltage input up to 160 V. Also, it has been observed that by increasing vibromotor voltage input beyond 160 V, mechanical properties were reduced significantly. It is also found that vibration time has less influence on the mechanical properties of weld connections. Improvement in hardness and ultimate tensile strength of vibratory welded joints is 16 and 14%, respectively, when compared without vibration, i.e. normal weld conditions. Average grain size is measured as per ASTM E 112–96. Average grain size is in the case of 0, 120, 160 and 230 is 20.709, 17.99, 16.57 and 20.8086 µm, respectively. Originality/value Novel vibratory TIG welded joints are prepared. Mechanical and micro-structural properties are tested.

Austenite Grain Evolution Mechanism of High Carbon Rail Based on Thermal Technology

2020 ◽  
Vol 837 ◽  
pp. 74-80
Author(s):  
Jun Yuan ◽  
Zhen Yu Han ◽  
Yong Deng ◽  
Da Wei Yang
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Rail Steel ◽  
Heating Temperature ◽  
Great Influence ◽  
Stable Operation ◽  
High Carbon ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Austenite Grains

In view of the special requirements of rails to ensure the safe and stable operation of Railways in China, the formation characteristics of austenite grains in high carbon rail are revealed through industrial exploration, the process of industrial rail heating and rolling is simulated, innovative experimental research methods such as different heating and heat treatment are carried out on the actual rails in the laboratory. Transfer characteristics of austenite grain size, microstructures and key properties of high carbon rail during the process are also revealed. The results show that the austenite grain size of industrial produced U75V rail is about 9.0 grade. When the holding temperature is increased from 800 C to 1300 C, the austenite grain size of high carbon rail steel decreases, the austenite grain are gradually coarsened, and the tensile strength increases slightly. The tensile strength is affected by the heating temperature. With the increase of heating temperature, the elongation and impact toughness of high carbon rail decrease. The heating temperature of high carbon rail combined with austenite grain size shows that the heating temperature has a great influence on austenite grain size, and has the most obvious influence on the toughness of high carbon rail.

Mechanical and Shielding Properties of an As-Cast New Pb-B Shielding Composite Materials

2010 ◽  
Vol 150-151 ◽  
pp. 56-63
Author(s):  
Yong Hua Duan ◽  
Yong Sun ◽  
Ming Jun Peng ◽  
Zhong Zheng Guo
Keyword(s):  
Tensile Strength ◽  
Sem Analysis ◽  
Radiation Shielding ◽  
Shielding Effect ◽  
High Tensile Strength ◽  
New Type ◽  
Γ Ray ◽  
Shielding Properties ◽  
Fractographic Examination ◽  
Scanning Electron

The new type of Pb-B shielding alloys with high tensile strength and hardness were prepared by casting. The microstructure and morphology of the Pb-B alloys were investigated by scanning electron microscope (SEM) analysis. Mechanical properties and radiation shielding effect of the alloys were compared with other Pb-based shielding alloys. The results indicate that the tensile strength and hardness increased up to 116 MPa and 160 HB with the 1.0 wt.% content of B. The fractographic examination conducted by SEM indicate that the Pb-B alloys are in form of plastic fracture, and the fracture model changes from the dimple to the intergranular quasi-cleavage with the increasing of B content. Furthermore, the composites are of the excellent shielding properties. Especially at the thickness of 20 mm, the shielding ratios for γ-ray and neutron reach 49.7% and 92.7%, respectively.

scholarly journals Study on Stability and Plastic Zone Distribution of Tunnel with Thin Carbonaceous Slate at Different Dip Angles

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jin Zhang ◽  
Chuanhao Xi ◽  
Qian Zhang ◽  
Mengxue Wang
Keyword(s):  
Tensile Strength ◽  
Plastic Zone ◽  
Field Measurement ◽  
Joint Angle ◽  
Rock Joint ◽  
Great Influence ◽  
Surrounding Rock ◽  
Test Field ◽  
Maximum Displacement ◽  
Dip Angle

Carbonaceous slate is heterogeneous and anisotropic, which has a great influence on the stability of tunnel. In this paper, by means of laboratory test, field measurement, and numerical simulation, the surrounding rock stability and plastic zone distribution characteristics of the carbonaceous slate tunnel at different intersection angles are analyzed. First, combined with the Haibaluo tunnel project, Brazilian splitting and uniaxial compression tests of jointed carbonaceous slate are performed. The test results show that the tensile strength of carbonaceous slate is related to joint dip angle. When the joint angle is 0°, the tensile strength is the largest and decreases with the increase of the joint angle. The uniaxial strength of rock decreases first and then increases. Based on the discrete fracture network (DFN) technology, a calculation model is established. The calculation results show that the maximum displacement is 0.45 m, when the dip angle of the surrounding rock joint is 45°. The field measurement also shows that the dip angle of the surrounding rock joint has an important influence on the distribution of the plastic zone. When the joint dip angle is 45°, the plastic zone develops most strongly.

scholarly journals On engineering of properties of wood-polypropylene composite

2006 ◽  
pp. 59-70 ◽  
Author(s):  
Milanka Djiporovic ◽  
Jovan Miljkovic ◽  
Eva Dingova
Keyword(s):  
Tensile Strength ◽  
Filler Content ◽  
Wood Flour ◽  
Beech Wood ◽  
Impact Resistance ◽  
High Strength ◽  
Polypropylene Composite ◽  
Elongation At Break ◽  
New Type ◽  
Polypropylene Matrix

New materials based on wood have the advantage in the sense that their properties can be engineered so as to correspond to user demands. The properties which can be engineered are those relating both to their utilisation and machining, in particular - the tensile strength, elongation at break, modulus of elasticity and impact resistance. The research at the Faculty of Forestry and "Hipol" Chemical Industry related to the new type of wood-polypropylene composite. The content of wood filler was varied in the range between 40% and 70% mass contents of beech wood flour. After the highest tensile strength at 50% of filler content was determined, the effect of the wood filler origin was also examined at this content value. Therefore, wood flour of beech, poplar, acetylated pine and the waste MDF was used. The influence of the composition of the wood filler (beech combined with MDF, poplar and acetylated pine) in comparison with pure polypropylene matrix was also examined, as well as the effect of the type of coupling agent. Hopefully, the results obtained in this study might serve as the initial data for production of easily machined high-strength composites.

Uplift behaviour of tapered piles established from model tests

2000 ◽  
Vol 37 (1) ◽  
pp. 56-74 ◽  
Author(s):  
M Hesham El Naggar ◽  
Jin Qi Wei
Keyword(s):  
Load Transfer ◽  
Compressive Loading ◽  
Compressive Load ◽  
Tensile Load ◽  
Confining Pressure ◽  
Cohesionless Soil ◽  
Uplift Capacity ◽  
Experimental Modelling ◽  
Confining Pressures ◽  
Load Tests

Tapered piles have a substantial advantage with regard to their load-carrying capacity in the downward frictional mode. The uplift performance of tapered piles, however, has not been fully understood. This paper describes the results of an experimental investigation into the characteristics of the uplift performance of tapered piles. Three instrumented steel piles with different degrees of taper were installed in cohesionless soil and subjected to compressive and tensile load tests. The soil was contained in a steel soil chamber and pressurized using an air bladder to facilitate modelling the confining pressures pertinent to larger embedment depths. The results of this study indicated that the pile axial uplift capacity increased with an increase in the confining pressure for all piles examined in this study. The ratios of uplift to compressive load for tapered piles were less than those for straight piles of the same length and average embedded diameter. The uplift capacity of tapered piles was found to be comparable to that of straight-sided wall piles at higher confining pressure values, suggesting that the performance of actual tapered piles (with greater length) would be comparable to that of straight-sided wall piles. Also, the results indicated that residual stresses developed during the compressive loading phase and their effect were more significant on the initial uplift capacity of piles, and this effect was more pronounced for tapered piles in medium-dense sand.Key words: tapered piles, uplift, axial response, load transfer, experimental modelling.

Effect of the Thick-Walled Steel Tubular Joint Stiffness on the Overall Stability of a Single-Layer Latticed Shell

2014 ◽  
Vol 501-504 ◽  
pp. 791-795
Author(s):  
Lan Chen ◽  
Bo Yin
Keyword(s):  
Great Influence ◽  
Joint Stiffness ◽  
Single Layer ◽  
Steel Tube ◽  
Tube Section ◽  
Overall Stability ◽  
Rectangular Tube ◽  
New Type ◽  
Tubular Joint ◽  
Geometric Nonlinear Analysis

As a new type of joint, the thick-walled steel tubular joint is applied in the single-layer latticed shell to solve the connectivity problem of rectangular tube. In combination with the design of practical project, the effect of the new joint stiffness on the overall stability of a single-layer latticed shell and the value of joint stiffness are studied by ANSYS. Some parameters as the rectangular tube section, the thickness of thick-walled steel tube and connecting plate are taken into account in the process of geometric nonlinear analysis. The results show that joint stiffness has great influence on the overall stability of a single-layer latticed shell and the range of effect gradually increases with the growth of rectangular tube section.

The Development of Thermostatically Biodegradable Composite

2021 ◽  
Vol 889 ◽  
pp. 44-49
Author(s):  
Yeng Fong Shih ◽  
Zheng Ting Chen ◽  
Wei Lun Lin ◽  
Po Chun Chiu ◽  
Chin Hsien Chiang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Polyethylene Glycol ◽  
Maleic Anhydride ◽  
Impact Strength ◽  
Polylactic Acid ◽  
Deformation Temperature ◽  
Thermal Deformation ◽  
Biodegradable Composite ◽  
New Type ◽  
Polybutylene Succinate

The purpose of this research is to develop a new type of environmentally friendly container which has thermostatic effect and is biodegradable. This study is based on polylactic acid (PLA) and maleic anhydride grafted polybutylene succinate (MAPBS). Subsequently, the diatomite which adsorbed polyethylene glycol (PEG) was added to prepare a thermostatic biodegradable composite. The addition of MAPBS is to improve the compatibility between PLA and diatomite. In addition, the thermostatic effect, tensile strength, thermal deformation temperature and impact strength of the composite were investigated.

Carbon fiber reinforced tin-superconductor composites

1989 ◽  
Vol 4 (6) ◽  
pp. 1339-1346 ◽  
Author(s):  
C. T. Ho ◽  
D. D. L. Chung
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Tensile Modulus ◽  
Tensile Load ◽  
Tensile Fracture ◽  
Fiber Direction ◽  
Continuous Carbon Fiber

Unidirectional and continuous carbon fiber tin-matrix composites were used for the packaging of the high-temperature superconductor YBa2Cu3O7–δ by diffusion bonding at 170 °C and 500 psi. Tin served as the adhesive and to increase the ductility, the normal-state electrical conductivity, and the thermal conductivity. Carbon fibers served to increase the strength and the modulus, both in tension along the fiber direction and in compression perpendicular to the fiber layers, though they decreased the strength in compression along the fiber direction. Carbon fibers also served to increase the thermal conductivity and the thermal fatigue resistance. At 24 vol. % fibers, the tensile strength was approximately equal to the compressive strength perpendicular to the fiber layers. With further increase of the fiber content, the tensile strength exceeded the compressive strength perpendicular to the fiber layers, reaching 134 MPa at 31 vol. % fibers. For fiber contents less than 30 vol. %, the compressive ductility perpendicular to the fiber layers exceeded that of the plain superconductor. At 30 vol. % fibers, the tensile modulus reached 15 GPa at room temperature and 27 GPa at 77 K. The tensile load was essentially sustained by the carbon fibers and the superconducting behavior was maintained after tension almost to the point of tensile fracture. Neither Tc nor Jc was affected by the composite processing.

Preparation of a New Type of Joint Filler and Study on Adhesion Performance

2014 ◽  
Vol 580-583 ◽  
pp. 674-678
Author(s):  
Xiao Wei Li ◽  
Chuan Sha
Keyword(s):  
Tensile Strength ◽  
Tensile Test ◽  
Concrete Pavement ◽  
Modified Bitumen ◽  
New Type ◽  
Adhesion Performance ◽  
Tensile Experiment ◽  
Better Than

Aiming at a new joint filler for pitch concrete pavement, processing it in different condition of water, determining the tensile strength through tensile experiment, analyzes the effect of adhesion performance from joint filler in water surrounding; does analysis to the adhesion performance of the recurrent tensile test in identical water surroundings.It evidenced that the new joint filler is much less affected in water surronuding than rubber modified bitumen,which is made by CARFCO inUSA,what meas that the new joint filler is much better than rubber modified bitumen on adhesion performance.

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