scholarly journals DESIGN AND FABRICATION OF CONCRETE-REINFORCED FLOATING PLATFORM FOR CANAL AND RIVER-SHORE PROTECTION

2021 ◽  
Vol 11 (4) ◽  
pp. 89-106
Author(s):  
Kreetha Somkeattikul ◽  
Chinnathan Areeprasert ◽  
Prysathyrd Sarabhorn ◽  
Thanya Kiatiwat
Keyword(s):  
Tensile Load ◽  
Steel Structure ◽  
Compression Stress ◽  
Shore Protection ◽  
Soil Environment ◽  
Floating Platform ◽  
Material Density ◽  
Cement Material ◽  
Maximum Compression Stress ◽  
Concrete Matrix

Erosion of canal and river-shore causes problems on agriculture activities and soil environment. This paper devotes to develop a floating platform to protect the shores. A concrete-reinforced floating platform was designed and fabricated in this study. Mechanical simulation was performed to ensure the design viability. The concrete-reinforced floating platform consists of three main parts: (1) steel structure, (2) foam-cement material, and (3) connecting joints. The dimension of the cement foam floating platform is 1.2 m in width, 3 m in length and 0.4 m in thickness. The cement used in this research is resistant to corrosion of sulfate and chloride from saltwater. Foam with density of 12 kg/m3 is mixed with concrete matrix so that the floating platform can float 60% or 0.16 m above the water surface. The foam cement material has the maximum compression stress of 1,951 kg ± 266.59 kg for the material density of 427.30 kg/m3 ± 19.30 kg/m3. The connecting joint part has the ultimate tensile load of 1,564 kg. The assemble floating platform has the compressive stress of 543.33 kg/m2 with the maximum vertical deformation of samples of 1 mm under the distribution load of 1,571 over the samples. Finally, from simulation with data from the material testing, the designed floating platform had a safety factor 3.46 which was higher than the design criteria of 3.

scholarly journals Comparison of Pigtail with J Anchor Bolt in Normal Concrete

2018 ◽  
Vol 150 ◽  
pp. 03001
Author(s):  
Mohamad Hairi Osman ◽  
Mohamad Nur Mustaqim Abd Shukor ◽  
Suraya Hani Adnan ◽  
Mohamad Luthfi Ahmad Jeni ◽  
Mohd Sufyan Abdullah ◽  
...  
Keyword(s):  
Load Capacity ◽  
Testing Machine ◽  
Tensile Load ◽  
Steel Structure ◽  
Maximum Load ◽  
Anchor Bolt ◽  
Average Value ◽  
Two Samples ◽  
Bending Radius ◽  
Anchor Bolts

Anchor bolts have been used to attach the steel structure of concrete and transfer load into the concrete. Anchor bolts in concrete are to withstand the shear force as they connect steel beams to the reinforced concrete foundations. The research was carried out to increase the understanding and investigating the performance of anchor bolts Pigtail since there is a lack of research on the bolt and to compare it with anchor bolts J which have been widely used by the industry. According to the methodology, testing the tensile load was used in this research to get a maximum load capacity of the anchor bolt in concrete. The sample was embedded in concrete cylinders of 75mm radius and 300mm height. Depths of embedment were 200mm, 230mm, and 260mm. The Universal Testing Machine, UTM was used to test the strength of tensile. 12 samples were used, each type and depth used two samples to get the average value using concrete grade 30. The samples underwent the process of curing for 28 days. The anchor bolts J used a 40mm bending radius and the length of hook was 100mm. Anchor bolts pigtail also used the 10 bending radius with depth of 8mm that have been compressed using 16mm radius rigs with a load of 500kN. Results of the research showed the depth of 260mm for Pigtail almost the same with J 60.529kN and 53.628kN and anchor bolts J were 75.557kN and 76.332kN. Difference of the values was not too far vary when compared with the 200mm and 230mm depths. Each comparison showed the ability of each bolt and anchor bolt failure occurred. Performance of the anchor bolts pigtail can be used on a structure or a higher load at an embedment of 260mm. Embedment of 200mm and 230mm can be used on a lighter load if steel material saving is a priority in every usage.

Compression Deformation Behavior of AZ91D Magnesium Alloy in Semi-Solid State

2007 ◽  
Vol 546-549 ◽  
pp. 151-154
Author(s):  
Ming Bo Yang ◽  
Fu Sheng Pan ◽  
Li Wen Tang ◽  
Hong Jun Hu
Keyword(s):  
Deformation Behavior ◽  
Deformation Rate ◽  
Deformation Temperature ◽  
Dendritic Structure ◽  
Isothermal Treatment ◽  
Compression Stress ◽  
Compression Strain ◽  
Compression Deformation ◽  
Maximum Compression Stress ◽  
Semi Solid

The semi-solid compression deformation behavior of the AZ91D alloy with non-dendritic structure, which was obtained under the semi-solid isothermal treatment condition of 570°C×60min, was studied by means of Gleeble-1500 thermal-mechanical simulator. When the compression strain was lower than 0.7, along with the compression strain increasing, the compression stress firstly increased rapidly, then decreased rapidly, and finally kept a constant stress level gradually. Under the condition of different deformation temperatures and deformation rates, the maximum compression stress was obtained simultaneously when the compression strain value was 0.025 approximatively. Furthermore, when the deformation rate kept a constant, the compression stress decreased along with the deformation temperature increasing, and when the deformation temperature kept a constant, the compression stress increased along with the deformation rate increasing.

Effect of Rare Earth Ce Addition on Microstructure and Properties of WCu Contact Materials

2011 ◽  
Vol 346 ◽  
pp. 148-153
Author(s):  
Xian Hui Wang ◽  
Jun Tao Zou ◽  
Bo Wang ◽  
Shu Hua Liang
Keyword(s):  
Electrical Conductivity ◽  
Rare Earth ◽  
Energy Dispersive Spectrometer ◽  
Compression Stress ◽  
Maximum Hardness ◽  
Contact Materials ◽  
Microstructure And Properties ◽  
Maximum Compression Stress ◽  
Infiltration Method ◽  
Scanning Electron

In order to clarify the effect of rare earth Ce on the microstructure and properties of WCu contact materials, different contents of Ce were introduced into W skeleton, and the relative density and compression stress of the pre-sintered W skeletons were tested. Subsequently, WCu contact materials with different contents of Ce were prepared by infiltration method. The hardness, electrical conductivity and the compression stress of WCu contact materials were tested, and the microstructure and composition were characterized by a scanning electron microscope equipped with an energy dispersive spectrometer. The results show that rare earth Ce can purify W/W interface and promote the densification of W skeleton, enhance the bonding of Cu/W, and improve the integral properties of WCu contact materials. In the range of experiments, WCu contact materials with 0.30wt%Ce addition has the maximum hardness of 215HB and the maximum compression stress of 900N/mm2, which are respectively increased by 23.60% and 57.20% in comparison with that without Ce addition.

scholarly journals Effect of Epoxy Coating on Structural Steel Section under Tension

2019 ◽  
Vol 9 (2) ◽  
pp. 2283-2288
Keyword(s):  
Structural Steel ◽  
Ultimate Load ◽  
Steel Plate ◽  
Tensile Load ◽  
Steel Structure ◽  
Breaking Load ◽  
Epoxy Coating ◽  
Displacement Curve ◽  
Cross Sectional ◽  
Bolt Holes

Structural steel connections are one of the most critical components of any steel structure as the cross-sectional area of steel sections reduces due to bolt holes. Failure of a structural connection may lead to failure of entire steel structure. Many researchers have tried to improve the connections previously by gluing fiber polymers at the connection. In this research glue or epoxy has been used around the bolt holes to simplify the process of using fiber polymers with steel. Epoxy is a combination of resin and hardener. It is proposed here to strengthen the structural steel connection in new structures and also in existing structures by applying a thin coat of suitable epoxy around the bolt hole. Thin steel plate with hole at the centre was tested under tensile load and results for ultimate load, breaking load, corresponding stresses and displacements obtained. Another steel plate with same geometry was then epoxy coated around the hole and same test was conducted on this specimen. Results for yield, ultimate, breaking loads and corresponding stresses and displacements recorded. The load-displacement curve is generated for both the cases and compared. The ultimate load bearing capacity of the plate increased in tension slightly after epoxy coating. Significant increase in breaking load observed as the thickness of epoxy layer was increased. Increase in the ductility of the composite plate is seen as increase in displacement is visible. There was considerable reduction of average stress around the center hole. The results indicate that structures can be safer against total failure and will give adequate warning before collapse.

An innovative approach for the assessment of masonry bridges based on two new limit analysis theorems

2019 ◽  
Author(s):  
Giuseppe Stagnitto ◽  
Alessandro Pederzani
Keyword(s):  
Structural Safety ◽  
Collapse Mechanism ◽  
Compression Stress ◽  
Plastic Hinges ◽  
Masonry Arch ◽  
Kinematic Method ◽  
Recent Theorem ◽  
Maximum Compression Stress ◽  
Masonry Arch Bridge ◽  
Kinematic Approach

<p>The structural safety of a masonry arch bridge is usually assessed using the so-called kinematic approach. In this paper it is proved that the adoption of the dual static method can be more convenient, since a recent theorem (the <i>Minimum Equilibrated Compression </i>theorem) makes its application straightforward for any kind of arch. Computations are checked via the kinematic method by locating the plastic hinges (as many as needed to form a collapse mechanism) in the sections with maximum compression stress. Thanks to the <i>Consecutive Plastic Hinges </i>theorem, the kinematic multiplier may be then evaluated, using familiar moments of forces, without computing the virtual displacements due to the vertical and horizontal loads acting on the arch.</p>

scholarly journals Optimization of Cold Pressing Process Parameters of Chopped Corn Straws for Fuel

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 652
Author(s):  
Tianyou Chen ◽  
Honglei Jia ◽  
Shengwei Zhang ◽  
Xumin Sun ◽  
Yuqiu Song ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Water Content ◽  
Specific Energy ◽  
Dimensional Stability ◽  
Specific Energy Consumption ◽  
Compression Stress ◽  
Stabilization Time ◽  
Stability Coefficient ◽  
Maintenance Time ◽  
Maximum Compression Stress

Pressed condensation is a key process before the reclamation of loose corn straws. In this study, the effects of stabilization time on the relaxation density and dimensional stability of corn straws were studied firstly, and then the stabilization time was determined to be 60 s by comprehensively considering the compression effect, energy consumption, efficiency and significance. On this basis, the effects of the water content (12%, 15%, 18%), ratio of pressure maintenance time to stabilization time (0, 0.5, 1), maximum compression stress (60.4, 120.8, 181.2 kPa) and feeding mass (2.5, 3, 3.5 kg) on the relaxation density, dimensional stability coefficient, and specific energy consumption of post-compression straw blocks were investigated by the Box–Behnken design. It was found that the water content, ratio of pressure maintenance time to stabilization time, maximum compression stress, and feeding mass all very significantly affected the relaxation density, dimensional stability coefficient and specific energy consumption. The interaction between water content and maximum compression stress significantly affected both relaxation density and specific energy consumption. The interaction between the ratio of pressure maintenance time to stabilization time and feeding mass significantly affected the dimensional stability coefficient. The factors and the indices were regressed by quadratic equations, with the coefficients of determination larger than 0.97 in all equations. The optimized process parameters were water content of 13.63%, pressure maintenance time of 22.8 s, strain maintenance time of 37.2 s, maximum compression stress of 109.58 kPa, and raw material feeding mass of 3.5 kg. Under these conditions, the relaxation density of cold-pressed straw blocks was 145.63 kg/m3, the dimensional stability coefficient was 86.89%, and specific energy consumption was 245.78 J/kg. The errors between test results and predicted results were less than 2%. The low calorific value of cold-pressed chopped corn straw blocks was 12.8 MJ/kg. Through the situational analysis method based on the internal and external competition environments and competition conditions (SWOT analysis method), the cold-pressed chopped corn straw blocks consumed the lowest forming energy consumption than other forming methods and, thus, are feasible for heating by farmers. Our findings may provide a reference for corn straw bundling, cold-press forming processes and straw bale re-compressing.

Effect of La Addition in W Skeleton on Microstructure and Properties of WCu Alloy

2010 ◽  
Vol 160-162 ◽  
pp. 1606-1610
Author(s):  
Bo Wang ◽  
Shu Hua Liang ◽  
Xian Hui Wang ◽  
Jun Tao Zou ◽  
Peng Xiao
Keyword(s):  
Electrical Conductivity ◽  
Rare Earth ◽  
Electron Microscope ◽  
Compression Stress ◽  
Sintering Process ◽  
Maximum Compression ◽  
La Addition ◽  
Maximum Compression Stress ◽  
Rare Earth La ◽  
Scanning Electron

In order to improve properties of WCu alloy, the different La were introduced into W skeleton during sintering process. The hardness, electrical conductivity and the compression stress were tested, and the microstructure and composition were characterized by a scanning electron microscope. The results show that an appropriate rare earth La addition can purify W/W interface, enhance the bonding of W /W, and improve the densification and the integral properties of WCu alloy. In the range of experiments, WCu alloy with 0.3wt% La addition has the largest hardness value of 198HB and the maximum compression stress of 823N/mm2. In comparison with that without La addition, 0.3wt%La addition decreases the electrical conductivity slightly, but improves the hardness and the maximum compression stress significantly, which are increased by 23.6% and 57.2%, respectively.

A Shelved Structure for the Support of An Electron Optical Column

1970 ◽  
Vol 28 ◽  
pp. 366-367
Author(s):  
P.H. McLaughlin
Keyword(s):  
Electron Source ◽  
Floating Platform ◽  
Supporting Structure

A shelved structure for the support of an electron optical column affords advantages both to the designer and the user. A lens may be removed for cleaning for example, without demounting the remaining lenses. A custom device for another example, may be placed on a shelf, substituting for the standard lens perhaps so that some specialized research may be undertaken. Especially advantageous is a shelved arrangement if the column assembly is designed to hang from a supporting structure such as a gas borne floating platform, as is the case with the system described below.As shown on the schematic, a floating platform (I) supports the electron source apparatus (2) and a U-shaped column support shelf (3). The column support shelf acts as a key for locating and supporting three struts (4) which with nuts (5) support the condenser shelf (6), the objective shelf (7), the upper projector shelf (8), and the lower projector shelf (9).

Specimen Collection Effect in Scanning Electron Microscopy Images

1972 ◽  
Vol 30 ◽  
pp. 448-449
Author(s):  
J. Temple Black ◽  
Jose Guerrero
Keyword(s):  
Surface Morphology ◽  
Secondary Electron Emission ◽  
Secondary Electrons ◽  
Charge Effects ◽  
Material Density ◽  
Specimen Collection ◽  
The Subject ◽  
Curved Paths ◽  
Subject Material ◽  
Microscopy Images

In the SEM, contrast in the image is the result of variations in the volume secondary electron emission and backscatter emission which reaches the detector and serves to intensity modulate the signal for the CRT's. This emission is a function of the accelerating potential, material density, chemistry, crystallography, local charge effects, surface morphology and especially the angle of the incident electron beam with the particular surface site. Aside from the influence of object inclination, the surface morphology is the most important feature In producing contrast. “Specimen collection“ is the name given the shielding of the collector by adjacent parts of the specimen, producing much image contrast. This type of contrast can occur for both secondary and backscatter electrons even though the secondary electrons take curved paths to the detector-collector.Figure 1 demonstrates, in a unique and striking fashion, the specimen collection effect. The subject material here is Armco Iron, 99.85% purity, which was spark machined.

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