Hydraulic Burst Test of X52 Pipes With Defects or Nozzle Repair Structure

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Xu Wu ◽  
Jian Shuai ◽  
Ke Shan ◽  
Kui Xu ◽  
Yan Di
Keyword(s):  
Bearing Capacity ◽  
Failure Mechanism ◽  
Safety Factor ◽  
Wall Thickness ◽  
Carrying Capacity ◽  
Burst Pressure ◽  
Burst Test ◽  
Relative Safety ◽  
Before And After ◽  
Blasting Test

Abstract Hydrostatic blasting test can be used to verify the bearing capacity of the pipeline in service. Spiral weld cracks and dents are common defects of pipes, and nozzle repair is a common repair method of perforated pipes. In order to determine the carrying capacity of the X52 pipeline with the above defects and the repaired structure, the corresponding pipe specimens were tested by hydraulic experiment, the yield pressure and burst pressure were recorded for each case. The axial and circumferential strains of the defect and repaired structure were measured in detail, the wall thickness and perimeter of the specimen before and after the experiment were measured, and the failure mechanism was analyzed. According to the relative safety factor in the standard, the bearing capacity of the pipeline was determined.

scholarly journals Kajian Stabilitas Lereng dengan Perkuatan Geotekstil dan Dinding Penahan Tanah Kantilever di Ruas Jalan Padang-Lb. Selasih Sumatera Barat

CANTILEVER ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 15-24
Author(s):  
Syahril Alzahri ◽  
Adiguna ◽  
Bimo Brata Adhitya ◽  
Yulindasari Sutejo ◽  
Reffanda Kurniawan Rustam
Keyword(s):  
Bearing Capacity ◽  
Safety Factor ◽  
Retaining Wall ◽  
Base Plate ◽  
Retaining Walls ◽  
Landslide Hazards ◽  
Before And After ◽  
Sliding Stability ◽  
Cantilever Retaining Walls ◽  
Plate Width

A typical relatively steep slope makes the Lb. Selasih – Bts. Kota Padang KM.29+650 experienced a landslide in 2017. So, it is necessary to strengthen the slope to overcome the landslide. Alternative slope reinforcement used is reinforcement using cantilever retaining walls or geotextiles. Slope stability analysis before and after were analyzed using the Slope/W program. The output produced by Slope/W program is the value of the safety factor. The safety factor value for the state of the original slope is 1.100. It shows that the slope in the original condition is unstable and vulnerable to landslide hazards. The retaining wall has a height of 11 m and a base plate width of 8 m. The results of the analysis showed that the cantilever retaining wall securely with stands shear, rolling, and bearing capacity of the subgrade with a safety factor value of 1.620; 1.550; 2.160, while geotextile reinforcement has a height of 16 m and an ultimate tensile strength of 200 kN / m. The results of the analysis showed that the reinforcement of the geotextile safely sliding, stability, and bearing capacity of the subgrade with a safety factor value of 1.600; 2.330; 2.860. Both of these reinforcements are safe to stabilize the slope by increasing the value of the slope safety factor by 2.235 for strengthening the cantilevered retaining wall and 2.279 for strengthening the geotextile.

scholarly journals Flexural bearing capacity and failure mechanism of CFRP-aluminum laminate beam with double-channel cross-section

2021 ◽  
Vol 28 (1) ◽  
pp. 139-152
Author(s):  
Teng Huang ◽  
Dongdong Zhang ◽  
Yaxin Huang ◽  
Chengfei Fan ◽  
Yuan Lin ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Bearing Capacity ◽  
Failure Mechanism ◽  
Cross Section ◽  
Failure Criterion ◽  
Failure Modes ◽  
Channel Cross Section ◽  
Fiber Layer ◽  
Flexural Bearing Capacity ◽  
Double Channel

Abstract In this study, the flexural bearing capacity and failure mechanism of carbon fiber-reinforced aluminum laminate (CARALL) beams with a double-channel cross-section and a 3/2 laminated configuration were experimentally and numerically studied. Two types of specimens using different carbon fiber layup configurations ([0°/90°/0°]3 and [45°/0°/−45°]3) were fabricated using the pressure molding thermal curing forming process. The double-channel CARALL beams were subjected to static three-point bending tests to determine their failure behaviors in terms of ultimate bearing capacity and failure modes. Owing to the shortcomings of the two-dimensional Hashin failure criterion, the user-defined FORTRAN subroutine VUMAT suitable for the ABAQUS/Explicit solver and an analysis algorithm were established to obtain a progressive damage prediction of the CFRP layer using the three-dimensional Hashin failure criterion. Various failure behaviors and mechanisms of the CARALL beams were numerically analyzed. The results indicated that the numerical simulation was consistent with the experimental results for the ultimate bearing capacity and final failure modes, and the failure process of the double-channel CARALL beams could be revealed. The ultimate failure modes of both types of double-channel CARALL beams were local buckling deformation at the intersection of the upper flange and web near the concentrated loading position, which was mainly caused by the delamination failure among different unidirectional plates, tension and compression failure of the matrix, and shear failure of the fiber layers. The ability of each fiber layer to resist damage decreased in the order of 90° fiber layer > 0° fiber layer > 45° fiber layer. Thus, it is suggested that 90°, 0°, and 45° fiber layers should be stacked for double-channel CARALL beams.

scholarly journals Evaluation of Bearing Capacity of Strip Footing Using Random Layers Concept

2015 ◽  
Vol 37 (3) ◽  
pp. 31-39 ◽  
Author(s):  
Marek Kawa ◽  
Dariusz Łydżba
Keyword(s):  
Monte Carlo ◽  
Bearing Capacity ◽  
Failure Mechanism ◽  
Design Theory ◽  
Cohesive Soil ◽  
Probability Of Failure ◽  
Mean Value ◽  
Strip Footing ◽  
Random Field Theory ◽  
The Mean

Abstract The paper deals with evaluation of bearing capacity of strip foundation on random purely cohesive soil. The approach proposed combines random field theory in the form of random layers with classical limit analysis and Monte Carlo simulation. For given realization of random the bearing capacity of strip footing is evaluated by employing the kinematic approach of yield design theory. The results in the form of histograms for both bearing capacity of footing as well as optimal depth of failure mechanism are obtained for different thickness of random layers. For zero and infinite thickness of random layer the values of depth of failure mechanism as well as bearing capacity assessment are derived in a closed form. Finally based on a sequence of Monte Carlo simulations the bearing capacity of strip footing corresponding to a certain probability of failure is estimated. While the mean value of the foundation bearing capacity increases with the thickness of the random layers, the ultimate load corresponding to a certain probability of failure appears to be a decreasing function of random layers thickness.

Investigation of Burst Pressure in T-Joints With Wall-Thinning by Using FEA

2017 ◽  
Author(s):  
Atsushi Yamaguchi
Keyword(s):  
Carrying Capacity ◽  
Safety Margin ◽  
Pressure Vessels ◽  
Burst Pressure ◽  
Load Carrying Capacity ◽  
Working Pressure ◽  
Element Analysis ◽  
T Joints ◽  
Wall Thinning ◽  
Load Carrying

Boilers and pressure vessels are heavily used in numerous industrial plants, and damaged equipment in the plants is often detected by visual inspection or non-destructive inspection techniques. The most common type of damage is wall thinning due to corrosion under insulation (CUI) or flow-accelerated corrosion (FAC), or both. Any damaged equipment must be repaired or replaced as necessary as soon as possible after damage has been detected. Moreover, optimization of the time required to replace damaged equipment by evaluating the load carrying capacity of boilers and pressure vessels with wall thinning is expected by engineers in the chemical industrial field. In the present study, finite element analysis (FEA) is used to evaluate the load carrying capacity in T-joints with wall thinning. Burst pressure is a measure of the load carrying capacity in T-joints with wall thinning. The T-joints subjected to burst testing are carbon steel tubes for pressure service STPG370 (JIS G3454). The burst pressure is investigated by comparing the results of burst testing with the results of FEA. Moreover, the maximum allowable working pressure (MAWP) of T-joints with wall thinning is calculated, and the safety margin for the burst pressure is investigated. The burst pressure in T-joints with wall thinning can be estimated the safety side using FEA regardless of whether the model is a shell model or a solid model. The MAWP is 2.6 MPa and has a safety margin 7.5 for burst pressure. Moreover, the MAWP is assessed the as a safety side, although the evaluation is too conservative for the burst pressure.

scholarly journals Effect of milking vacuum level and overmilking on cows’ teat characteristics

2011 ◽  
Vol 59 (5) ◽  
pp. 193-202 ◽  
Author(s):  
M. Pařilová ◽  
L. Stádník ◽  
A. Ježková ◽  
L. Štolc
Keyword(s):  
Wall Thickness ◽  
Treatment Effects ◽  
Vacuum Level ◽  
Milk Flow ◽  
Before And After ◽  
Teat Canal ◽  
Test Treatment

The influence of milking vacuum and milk flow level (resp. detachment level) on cows’ teat characteristics were studied in four experiments. The MIXED procedure was used to test treatment effects on the level of teat length, teat thickness at the base and half-way between the teat end and the base of udder, teat canal length, teat end width, teat wall thickness, teat cistern width after milking and on differences between these teat characteristics measured before and after milking. A total of 51 cows were included in all experiments. All the cows had clinically healthy udders. Some cows were involved in two or more experiments. Finally, 330 teat measurements of 165 cows were taken and statistically processed. Vacuum and milking with or without overmilking significantly (P < 0.05-0.001) influence monitored parameters. Milking vacuum has an influence on two of three measured external teat parameters: teat diameter measured at the base of the teat and half-way between the udder base and the teat tip. Change in teat length measured before and immediately after milking was higher when higher vacuum of 45 kPa was used. Detachment level also has an influence on teat proportions. Overmilked teats were longer and narrower compared to non-overmilked teats. Interaction between milking vacuum and detachment level influences external teat parameters as well.

Experiment and Simulation Analysis of the Pressure Carrying Capacity of X80 Pipe with Metal Loss Defect on the Girth Weld

2021 ◽  
Vol 1035 ◽  
pp. 813-818
Author(s):  
Zheng Long Li ◽  
Lin Chen ◽  
Zhi Hong Li ◽  
Guo Shuai Yan ◽  
Wei Li
Keyword(s):  
Sensitivity Analysis ◽  
Carrying Capacity ◽  
Simulation Analysis ◽  
Water Pressure ◽  
Metal Loss ◽  
Factors Affecting ◽  
Element Simulation ◽  
Simulation Based ◽  
Blasting Test ◽  
Water Pressure Blasting

In order to study the pressure carrying capacity of X80 pipe with metal loss defect on the girth weld the water-pressure blasting test of the pipe with metal loss defect was analyzed by experiment and finite element simulation. Based on this, the sensitivity analysis of the factors affecting the pressure carrying of the pipeline, such as the circular size, the axial size, and the depth of the metal loss defect, was carried out. The research results show that the circular size of the metal loss defect on the girth weld had little impact to the pressure carrying capacity of the pipe while it reduced with the increasing of the axial size and the depth of the metal loss defect.

SEISMIC ASSESSMENT OF CONTEMPORARY VERSUS OLD URBAN FRAME BUILDINGS

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
ABDELRAHMAN ASHRI ◽  
ANAS ISSA ◽  
Aman Mwafy
Keyword(s):  
Comparative Study ◽  
Lateral Force ◽  
Fragility Functions ◽  
Seismic Code ◽  
Earthquake Losses ◽  
Relative Safety ◽  
Safety Margins ◽  
Before And After ◽  
Benchmark Structures ◽  
The Comparative Study

This comparative study probabilistically assesses the relative safety margins of code-compliant and pre-seismic code RC buildings with different heights in a region of medium seismicity. Detailed structural design and fiber-based modeling of six benchmark structures, namely two code-compliant buildings and two pre-code structures before and after retrofit, are undertaken to develop fragility functions using several earthquake records representing the most critical seismic scenario in the study area. Several inelastic dynamic analyses are performed to assess the seismic response and derive a range of fragility functions for the six benchmark buildings. Compared with contemporary structures, the study highlights the vulnerability of pre-code buildings due to the insufficient stiffness, strength, and ductility provided by their lateral force resisting systems. A practical retrofit solution for pre-code structures is subsequently assessed using the methodology adopted for other modern and old buildings. The probabilistic assessment results confirmed the comparable seismic performance of the retrofitted and code-conforming buildings. The comparative study, which provided insights into the differences between code-compliant versus pre-seismic code buildings before and after retrofit, contributes to reducing earthquake losses and improving community seismic resilience in earthquake-prone regions.

Sign in / Sign up

Export Citation Format

Share Document