Numerical simulation of the failure behavior of steam-side oxide scale considering oxide creep and physical defects

2017 ◽  
Vol 69 (2) ◽  
pp. 215-226 ◽  
Author(s):  
J. Qi ◽  
K.-Y. Zhou ◽  
J.-L. Huang ◽  
X.-D. Si
Keyword(s):  
Numerical Simulation ◽  
Oxide Scale ◽  
Failure Behavior ◽  
Physical Defects

scholarly journals NUMERICAL SIMULATION OF FAILURE BEHAVIOR AND CRACK PROPAGATION OF ROCK SLOPE BY 3D DEM

2008 ◽  
Vol 64 (3) ◽  
pp. 607-615
Author(s):  
Satoshi OHTSUKI ◽  
Harushige KUSUMI ◽  
Toshifumi MATSUOKA
Keyword(s):  
Numerical Simulation ◽  
Crack Propagation ◽  
Rock Slope ◽  
Failure Behavior

scholarly journals Failure Behavior of F Shape Non-Persistent Joint under Experimental and Numerical Uniaxial Compression Test

2021 ◽  
Author(s):  
vahab sarfarazi ◽  
kaveh asgari ◽  
meisam zarei
Keyword(s):  
Numerical Simulation ◽  
Compression Test ◽  
Experimental Testing ◽  
Failure Process ◽  
Particle Flow Code ◽  
Failure Behavior ◽  
Uniaxial Compression Test ◽  
Joint Angles ◽  
Large Joint ◽  
Load Rate

Abstract Experimental and discrete element approaches were used to examine the effects of F shape non-persistent joints on the failure behaviour of concrete under uniaxial compressive test. concrete specimens with dimensions of 200 mm×200 mm×50 mm were provided. Within the specimen, F shape non-persistent joint consisting three joints were provided. The large joint length was 6 cm, and the length of two small joints were 2cm. Vertical distance betwenn two small joints change from 1.5 cm to 4.5 cm with increment of 1.5 cm. In constant joint lengths, the angle of large joint change from 0 to 90 with increments of 30. Totally 12 different models were tested under compression test. The axial load rate on the model was 0.05 mm/min. Cuncurrent with experimental tests, numerical simulation (Particle flow code in two dimension) were performed on the models containing F shape non-persistent joint. Distance between small joints and joint angles were similar to experimental one. the results indicated that the failure process was mostly governed by both of the Distance between small joints and joint angles. The compressive strengths of the samples were related to the fracture pattern and failure mechanism of the discontinuities. Furthermore it was shown that the compressive behaviour of discontinuities is related to the number of the induced tensile cracks which are increased by increasing the joint angle. In the first There were only a few AE hits in the initial stage of loading, then AE hits rapidly grow before the applied stress reached its peak. Furthermore, a large number of AE hits accompanied every stress drop. Finally, the failure pattern and failure strength are similar in both approaches i.e. the experimental testing and the numerical simulation approaches.

Numerical simulation and life prediction on T22 boiler tubes with steam-side and fire-side oxide scale

2018 ◽  
Vol 36 (2) ◽  
pp. 125-131 ◽  
Author(s):  
Heng-Chao Guo ◽  
Dong-Mei Ji ◽  
Jia-Zhi Tang ◽  
Quan Sun ◽  
Chen Dai ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Oxide Scale ◽  
Life Prediction ◽  
Boiler Tubes

Spot Weld Property Testing and Simulation Modeling with Failure Criteria

2013 ◽  
Vol 284-287 ◽  
pp. 198-203
Author(s):  
Hsiu Ying Hwang ◽  
Nguyen Quoc Nghiem
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Simulation Model ◽  
Weld Zone ◽  
Tensile Tests ◽  
Spot Weld ◽  
Vehicle Body ◽  
Failure Behavior ◽  
Heat Treated ◽  
Spot Welded

Spot welds have been widely used in vehicle body assembly, and can affect the performance of a vehicle. This paper studies the mechanical properties of spot weld and utilizes those properties in the numerical simulation to predict the failure behavior of a spot-welded component. The mechanical properties of a spot weld are not easy to obtain due to the size of spot weld, and the non-uniformity around the weld zone. The study utilized the hardness measured on and around the spot weld, heat treated samples with the same hardness, and then performed the tensile tests on those heat treated specimens to obtain the corresponding mechanical properties. With those testing data, the numerical simulation model was then created based on the properties obtained. A single-spot-welded part was used to correlate the results of hardware tests and numerical simulation. The study compared the results of three different modeling schemes with those of the hardware test. The results showed that the simulation model with material properties assigned to their corresponding region provided better correlation with the hardware testing results.

Numerical Simulation of Ice Ridge Gouging

2015 ◽  
Author(s):  
Lei Liu ◽  
Eleanor Bailey ◽  
Robert Sarracino ◽  
Rocky Taylor ◽  
Colin Power ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Source Code ◽  
Three Dimensional ◽  
Friction Angle ◽  
The Arctic ◽  
Failure Behavior ◽  
Test Program ◽  
Constant Friction ◽  
Model Features ◽  
Shear Bending

In coastal regions throughout the Arctic, the seabed is frequently scoured or gouged by sea ice ridges and icebergs. This presents an environmental hazard to pipelines or subsea infrastructures operating in the area and therefore a greater understanding of these processes is needed. This paper describes a three dimensional (3D), numerical model that was developed to simulate the failure behavior of a ridge keel as it interacts with the seabed. The simulation was conducted in Yade, an open-source code, which uses the Discrete Element Method (DEM) to model particle motions. The ice blocks in the ridge keel are modeled as spheres, which are initially bonded to contacting blocks via freeze-bonds. A Cohesive Frictional Model (CFM) which has cohesive bonds in tension and shear was used to simulate the freeze-bonds between ice blocks. In addition to normal and shear bonds, the model features springs which resist compression, shear, bending and torsion. Once the bonds are broken the material is assumed to behave like a Mohr-Coulomb material with a constant friction angle. Since the main focus of this paper is the failure behavior of the keel, the seabed is simplified as being rigid. Numerical simulation is compared with data collected from the Pipeline Ice risk Assessment and Mitigation (PIRAM) test program.

scholarly journals Numerical Simulation of Failure Behavior of Granular Debris Flows Based on Flume Model Tests

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Jian Zhou ◽  
Ye-xun Li ◽  
Min-cai Jia ◽  
Cui-na Li
Keyword(s):  
Numerical Simulation ◽  
Debris Flow ◽  
Numerical Simulations ◽  
Failure Mode ◽  
Debris Flows ◽  
Fine Particles ◽  
Model Tests ◽  
Failure Behavior ◽  
Medium Sand ◽  
Grain Sizes

In this study, the failure behaviors of debris flows were studied by flume model tests with artificial rainfall and numerical simulations (PFC3D). Model tests revealed that grain sizes distribution had profound effects on failure mode, and the failure in slope of medium sand started with cracks at crest and took the form of retrogressive toe sliding failure. With the increase of fine particles in soil, the failure mode of the slopes changed to fluidized flow. The discrete element methodPFC3Dcan overcome the hypothesis of the traditional continuous medium mechanic and consider the simple characteristics of particle. Thus, a numerical simulations model considering liquid-solid coupled method has been developed to simulate the debris flow. Comparing the experimental results, the numerical simulation result indicated that the failure mode of the failure of medium sand slope was retrogressive toe sliding, and the failure of fine sand slope was fluidized sliding. The simulation result is consistent with the model test and theoretical analysis, and grain sizes distribution caused different failure behavior of granular debris flows. This research should be a guide to explore the theory of debris flow and to improve the prevention and reduction of debris flow.

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