Experimental study on mechanical behavior of combined joint using adhesives and high strength bolts

2021 ◽  
Author(s):  
Takuya Kamino ◽  
Takashi Fujimoto ◽  
Takashi Yamaguchi ◽  
Yasumoto Aoki ◽  
Shinsuke Akamatsu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Design Method ◽  
High Strength ◽  
Corrosion Damage ◽  
Epoxy Adhesive ◽  
Steel Bridge ◽  
Slip Coefficient ◽  
Constraint Effect ◽  
Slip Resistance

<p>As a repair for corrosion damage of a steel bridge, a patch plate-repair using high strength bolts is generally applied. This method requires the surface of the damaged corroded part filled with an epoxy adhesive flat. The load transferring mechanism and slip resistance of such a combined joint with adhesives and high strength frictional bolts aren't clear. Since the shear strength of an adhesive might be increased due to constraint by the bolt axial force, the combined joint's slip resistance would be increased. To clarify the mechanical properties of the combined joint and to propose a new design method for such joints, two experiments have been conducted. The first was a frictional force experiment for adhesive specimens subjected to contact pressure on the surface to evaluate the constraint effect of adhesive on shear strength quantitatively. The last one is a slippage experiment for the combined joints to evaluate its slip coefficient.</p>

scholarly journals Effect of Microstructure and Texture on Mechanical Properties of Resistance Spot Welded High Strength Steel 22MnB5 and 5A06 Aluminium Alloy

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 685
Author(s):  
Xiaoqing Jiang ◽  
Shujun Chen ◽  
Jinlong Gong ◽  
Zhenyang Lu
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Aluminium Alloy ◽  
High Strength Steel ◽  
High Strength ◽  
Welding Parameters ◽  
Tensile Shear Strength ◽  
Tensile Shear ◽  
Resistance Spot ◽  
Effect Of Microstructure

The present study aims to investigate the effect of microstructure and texture on mechanical properties of resistance spot welding of high strength steel 22MnB5 and 5A06 aluminium alloy as a function of welding parameters. The pseudo-nugget zones (NZs) at the steel side have undergone full recrystallisation with a fine-grained ferrite structure containing a small amount of retained austenite and a high hardness of approximately 500 HV, which is a 35% increase in hardness compared to the base material (BM) with fine lath martensitic structure. The NZs at the Al side contain both a recrystallisation texture and shear texture. Higher tensile shear strength with increasing weld time could be linked to the random texture at the Al side. The highest tensile shear strength was achieved at an intermetallic layer thickness of 4 mm.

Test Study of Shear Strength of High Strength Stone Masonry

2010 ◽  
Vol 452-453 ◽  
pp. 365-368 ◽  
Author(s):  
Da Lin Hu ◽  
Feng Cheng ◽  
Long Gang Chen
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
High Strength ◽  
Stone Masonry ◽  
Aggregate Concrete ◽  
Long Span ◽  
Test Study ◽  
Design Value ◽  
Concrete Joints ◽  
Arch Bridges

In China many long span stone arch bridges were built in the last 5 decades, most of these bridges were built with micro-aggregate concrete joint masonry. However, the mechanical properties of this kind masonry have been seldom studied. Based on 5 groups of specimens with C30 or C40 micro-aggregate concrete joints and dressed blocks, shear strength of the masonry is tested and analyzed, friction coefficients and empiric formulas of shear strength of the masonry are presented in this paper, design value of shear strength of the masonry is assessed and discussed.

UDIMAR B-300

Alloy Digest ◽  
1969 ◽  
Vol 18 (9) ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
Precipitation Hardening ◽  
Cobalt Content ◽  
High Strength ◽  
Heat Treating ◽  
Temperature Performance ◽  
Strength Alloy

Abstract UDIMAR B-300 is an 18% nickel maraging steel having excellent toughness and ductility at high strength levels. It is a fabricable and weldable ultra-high strength alloy steel combining the mechanical properties derived from precipitation hardening and martensitic transformation. It has increased cobalt content compared with UDIMAR B-250 (Alloy Digest SA-206, February 1967). This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fracture toughness, creep, and fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-244. Producer or source: Special Metals.

Mechanical properties of Ficus vallis-choudae (Delile), a lesser utilized species in Nigeria

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 6550-6560
Author(s):  
Lawrence Aguda ◽  
Babatunde Ajayi ◽  
Sylvester Areghan ◽  
Yetunde Olayiwola ◽  
Aina Kehinde ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Moisture Content ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
High Strength ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Impact Bending ◽  
Timber Market

Declining availability of the prime economic species in the Nigerian timber market has led to the introduction of Lesser-Used Species (LUS) as alternatives. Their acceptability demands information on the technical properties of their wood. The aim of this study was to investigate the mechanical properties of Ficus vallis-choudae to determine its potential for timber. Three mature Ficus vallis-choudae trees were selected and harvested from a free forest area in Ibadan, Oyo State, Nigeria. Samples were collected from the base (10%), middle (50%), and top (90%) along the sampling heights of each tree, which was further partitioned into innerwood, centrewood, and outerwood across the sampling radial position. Investigations were carried out to determine the age, density, moisture content, impact strength, modulus of elasticity, modulus of rupture, compressive strength parallel-to-grain, and shear strength parallel-to-grain. The mean impact bending strength, modulus of rupture, modulus of elasticity, maximum shear strength parallel-to-grain, and maximum compression strength parallel-to-grain for Ficus vallis-choudae at 12% moisture content were 20.4 N/mm2, 85.8 N/mm2, 709 N/mm2, 10.7 N/mm2, and 33.6 N/mm2, respectively. The study found the species to be dense with high strength properties in comparison with well-known timbers used for constructional purposes.

Inter-Laminar Mechanical Properties Improvements in Carbon Nanotubes Reinforced Laminated Nanocomposites

2011 ◽  
Author(s):  
Davood Askari ◽  
Mehrdad N. Ghasemi-Nejhad
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Shear Strength ◽  
Epoxy Adhesive ◽  
Lap Joints ◽  
Carbon Cloth ◽  
Fibrous Materials ◽  
Thickness Direction ◽  
Single Lap Joints ◽  
Vertically Aligned

Owing to their superior mechanical properties, carbon nanotubes (CNTs) can be used as an additional reinforcement to improve the mechanical properties of laminated composite materials. To incorporate the excellent properties of CNTs into the existing traditional composite technology, vertically aligned high density arrays of CNTs were grown perpendicular to the surface of 2-D woven cloths and tows of various fibrous materials. The nano-forest like structures of fabrics is used to fabricate 3-D reinforced nanocomposites. Due to the presence of aligned CNTs in through-the-thickness direction, it is expected that the inter-laminar and through-the-thickness properties of the composite laminate will be improved considerably. To demonstrate the effectiveness of our approach, various composite single lap-joint specimens were fabricated for inter-laminar shear strength testing. Carbon woven cloths with and without CNTs nano-forests were inserted in between the single lap-joints using epoxy adhesive to measure the interlaminar shear strength improvements due to the presence of through-the-thickness aligned CNTs nano-forests. It is observed that single lap-joints with carbon cloth insertion layers having CNTs nano-forest can carry up to 12% higher shear stress and 16% higher strain-to-failure. The failures of samples with nano-forests were completely cohesive while the sample with carbon woven cloth insertion failed adhesively. This concludes that the adhesion of adjacent carbon fabric layers can be considerably improved due to the growth of vertically aligned CNTs nano-forest in through-the-thickness direction.

scholarly journals Experimental Study on Mechanical Properties of a Medium Size Box-Type Corrugated Steel Bridge

2021 ◽  
Author(s):  
Wenqiang Fu ◽  
Xinsha Fu ◽  
Yuting He ◽  
Baijian Li
Keyword(s):  
Mechanical Properties ◽  
Dynamic Load ◽  
Static Load ◽  
Design Method ◽  
Axial Stress ◽  
Structure Design ◽  
Steel Bridge ◽  
Maximum Value ◽  
Box Structure ◽  
Load Conditions

Different from an arch bridge, the load-carrying capacity of a box structure mainly depends on the bending capacity of corrugated steel. This paper explores the mechanical properties of a corrugated steel box bridge. The mechanical properties of a 13 m span corrugated steel box bridge under static and dynamic loads were tested. Three static load conditions were tested, and four dynamic load conditions were tested, including 20 km/h, 40 km/h, 60 km/h, and 80 km/h. Through the analysis of section strain, vault displacement, dynamic strain, and internal force, the following conclusions can be drawn: (1) when the static load changes from the right arch foot and vault to the left arch foot, the strain value of each measuring point continues to increase, which may be caused by the accumulation of deformation due to the adjustment of the stress state of the soil and corrugated steel caused by loading; (2) the displacement change in the test is more sensitive than the strain change; (3) the vault strain reaches the maximum value at a specific speed of 60 km/h. This is related to the structural resonance caused by vehicle operation, and the natural frequency of the corrugated steel box bridge can be determined by a field vehicle dynamic load test; (4) the damping value of an embedded corrugated steel bridge is large, and the energy dissipation capacity is strong, which is very beneficial to structural earthquake resistance and to reducing the structural resonance under traffic load; (5) the dynamic increasing strain coefficient is less than 1, which means that the strain caused by a dynamic load is far less than that caused by a static load, and it reaches the maximum value at a certain speed (60km/h); (6) the maximum bending stress and maximum axial stress of the corrugated steel box bridge tested in this paper are basically the same, which indicates that the axial stress of the box structure cannot be ignored. However, the box structure design method proposed in the CHBDC code does not consider the axial stress, so it is necessary to further improve the box structure design method; (7) most of the axial force of a box corrugated steel bridge is tensile force. The pavement structure layer has an effect on the overall performance of the corrugated steel box bridge, which is similar to the decompression plate: it makes the overall stress (I ∼ V section) more uniform and the bending moment smaller.

Tests on Mechanical Properties and Anti-Explosion Performance of Steel-Fiber Reactive Powder Concrete

2011 ◽  
Vol 368-373 ◽  
pp. 436-440
Author(s):  
Chun Ming Song ◽  
Ming Yang Wang ◽  
De Rong Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Compressive Strength ◽  
Shear Strength ◽  
Steel Fiber ◽  
High Strength ◽  
Reactive Powder Concrete ◽  
Compression Coefficient ◽  
Reactive Powder ◽  
Very High

In order to get mechanical properties and anti-explosion capability parameters, some RPC samples with 5% steel fiber are tested, many groups data were obtained such as compressive strength, shear strength and fracture toughness. The model tests are also carried out on RPC shelter plate under contact explosion, the most important parameter to express anti-explosion capability,i.e. compression coefficient of the material, is obtained by above experiments and theory study, the results of tests show RPC with steel fiber has very high strength and anti-explosion capability, its compressive strength and anti-explosion capability are about six and three times higher than those of C30 concrete respectively.

UDIMAR B-250

Alloy Digest ◽  
1967 ◽  
Vol 16 (2) ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
Martensitic Transformation ◽  
Precipitation Hardening ◽  
High Strength ◽  
Heat Treating ◽  
Temperature Performance ◽  
Very High

Abstract UDIMAR B-250 is a fabricable and weldable ultra-high strength maraging steel combining the mechanical properties derived from precipitation hardening and martensitic transformation. It exhibits very high ultimate and yield strengths combined with excellent ductility and notched/unnotched ratio. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fracture toughness and fatigue. It also includes information on low temperature performance and corrosion resistance as well as forming, heat treating, joining, and surface treatment. Filing Code: SA-206. Producer or source: Special Metals.

Study on after-slip strength of high-strength bolted frictional joints with a filler plate

2021 ◽  
Author(s):  
Masaki Fujiwara ◽  
Takashi Yamaguchi ◽  
Senju Kozai
Keyword(s):  
Shear Strength ◽  
Shear Failure ◽  
Plate Thickness ◽  
High Strength ◽  
Highway Bridges ◽  
Tensile Tests ◽  
Reduction Factor ◽  
Design Strength ◽  
Slip Resistance ◽  
Frictional Joints

<p>According to the new Japanese Specifications for Highway Bridges, after-slip behavior should be verified in high-strength bolted frictional joints. Previous studies have investigated slip behavior with a filler plate. They have proposed the reduction factor of slip resistance. On the other hand, the ultimate strength of such a joint with a filler plate is not clear, and its design strength considering after-slip behavior is not also specified. In this study, for high-strength bolted frictional joints with various filler plate thicknesses, tensile tests and FEA were carried out. From obtained results, it was revealed that a filler plate did not resist load in bearing, and the number of bolt shear failure surfaces was decreased to one from two by a filler plate. It is also found that bolt shear strength decreased below the designed value as filler plate thickness is increased. The authors also proposed the simple design model for bolt shear strength in the frictional joints with a filler plate.</p>

Slip coefficient of 90-year-old riveted joint surface with red lead paint for corrosion

2021 ◽  
Author(s):  
Yu Chen ◽  
Takashi Yamaguchi ◽  
Motoshi Yamauchi ◽  
Keita Ueno
Keyword(s):  
Pressure Distribution ◽  
High Strength ◽  
Joint Surface ◽  
Steel Bridge ◽  
Slip Coefficient ◽  
Lead Paint ◽  
Riveted Joints ◽  
Riveted Joint ◽  
Red Lead ◽  
Joint Section

<p>Before 1950, steel bridges were basically connected by rivets. Most of the steel bridge has been replaced due to aging or corrosion. However, many rivet bridges are still being in service; some of the rivets might be corroded and loosen due to the paint coating's deterioration. The riveted bridge has to repair by replacing the corroded rivets with high-strength bolts for friction connection. However, the slip coefficient of riveted joint surfaces with red lead treatment is not specified. In this study, specimens cut out from a 90-year-old riveted bridge's joint section and evaluated the riveted joint surface's aging condition by microscope observation and elemental analysis. The slip and pressure distribution tests are also conducted to investigate the slip coefficient and pressure distribution of riveted joints' surface. It is found that the joint surface is not flat, the average slip coefficient is 0.274, and the −2&#120590; is calculated to 0.169.</p>

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