Pipe Knocked From Supports by Hydraulic Transient Event

2020 ◽  
Author(s):  
Lawrence M. Matta ◽  
Jacob Manuel ◽  
Sathish Ramamoorthy
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Plastic Strain ◽  
Product Lines ◽  
Element Analysis ◽  
Transient Event ◽  
Hydraulic Transient ◽  
Start Up ◽  
Discharge Valve ◽  
The Impact

Abstract Following what was considered a routine realignment of liquid product lines and tankage at a storage and transfer facility, an incident occurred that resulted in significant movement of a 20-inch pipeline, causing a large section of it to fall from its supports. The event also resulted in the failure of a gasket at a valve flange and loss of containment. The alignment activities and pump startup were investigated for the potential to generate a hydraulic transient capable of generating sufficient force to cause the movement. A transient hydraulic model of the fluid in the piping as it was aligned at the time of the event was generated to assist in determining the cause and to help prevent a similar occurrence in the future. Several scenarios were modeled and are discussed in this paper: 1) pump shutdown from steady flow, 2) pump start up with the discharge valve open, 3) pump startup with the discharge valve closed, and 4) pump start up with a vapor cavity present near a closed valve at the high point in the line. Pipe stress and finite element analysis were used to assess the displaced pipe and to determine if it could be placed back into service. The piping stress analysis indicated that the highest stress in the piping was below the yield stress of the material. Results from a detailed finite element analysis with material nonlinearity confirmed that there was no global plastic strain in the piping due to the event. This left a potential for local plastic strain due to the impact of the pipe against any hard surfaces, and this was addressed with visual examination. In the end, the pipe was lifted back onto the supports, lateral restraints were added at pipe support locations, and procedural changes were implemented to reduce the likelihood of future events.

Finite Element Analysis of Particle Impact on Substrates Using HVOF Thermal Spray Coating

2016 ◽  
Vol 852 ◽  
pp. 446-451
Author(s):  
Vaibhav Shelar ◽  
D. Davidson Jebaseelan ◽  
C.P. Karthikeyan ◽  
Joseph Stokes
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Plastic Strain ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Flame Spray ◽  
Element Analysis ◽  
Hvof Thermal Spray ◽  
The Impact

Lower flame temperature characteristics of high velocity oxygen fuel (HVOF) flame spray process favor several surface coating applications. Simulation of HVOF coating is extremely complex to analyze, since its properties and microstructure depend on numerous processing parameters. Finite element analysis (FEA) is used in this paper to analyze the influence of particle heat input and impact velocity on HVOF coating on various substrates. HVOF thermal spray coating conditions, Tungsten Carbide Cobalt (WC-Co) particles and steel substrate were modeled using ANSYS 14.5. Droplets of different size were considered as particles in the numerical analysis to study their impact on the substrate. Thermal and residual stress analysis was done on both the particle and substrate during different stages of the high velocity impact process. Both rigid and soft conditions of the particle and substrate were simulated. Thermal stress of both the particle and substrate were found to increase rapidly very close to the impact process. Smaller sized particles had higher plastic strain when compared to larger sized particles. However, the residual stress and plastic strain of the substrate increased when impacted by larger sized particles. Residual stress of both particle and substrate were found to be influenced by the impact and thermal stress of each other. Higher velocity of the flame spray showed improved plastic strain and stress on individual particles, which is a major reason for the dense pattern of coating.

Flexible Flowline Walking Tendency on Seabed With Longitudinal Undulations and Transverse Gradients

2018 ◽  
Author(s):  
Graeme Roberts ◽  
T. Sriskandarajah ◽  
Gianluca Colonnelli ◽  
Arnaud Roux ◽  
Alan Roy ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Temperature Gradients ◽  
Radius Of Curvature ◽  
Bend Radius ◽  
Lateral Buckling ◽  
Element Analysis ◽  
Slip Tendency ◽  
Start Ups ◽  
The Impact

A method of carrying out a combined axial walking and lateral buckling assessment for a flexible flowline has been developed using finite element analysis. The method overcomes limitations of screening assessments which could be inconclusive when applied either to a flexible flowline on an undulating seabed with transverse gradients or to one that buckles during hydrotest. Flexible flowlines that were to be surface-laid on a seabed with longitudinal undulations and transverse gradients were assessed using the method. The flexible flowlines were simulated in their as-laid state, and the simulation incorporated hydrotest pressure and the pressure & temperature gradients and transients associated with multiple start-ups. The objective was to quantify the axial walking and lateral slip tendency of the flexible flowlines and the impact that walking might have on the connected end structures. The lateral buckle locations predicted by finite element analysis were compared to a post-hydrotest survey and the radius of curvature from analysis was compared to the minimum bend radius of the flexible.

scholarly journals Finite Element Analysis-Aided Performance Improvement of Circular Coil Assemblies Applied in Electric Vehicle Inductive Chargers

2021 ◽  
Author(s):  
Guodong Zhu ◽  
Dawei Gao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Electric Vehicle ◽  
Performance Improvement ◽  
Magnetic Circuit ◽  
Element Analysis ◽  
System Parameters ◽  
Leakage Magnetic Field ◽  
Fea Simulation ◽  
The Impact

Energy efficiency and leakage magnetic field (LMF) are two important issues in inductive chargers. In this work, the maximum achievable coil efficiency and the corresponding LMF strength are formulated as functions of system parameters, and figure of merits (FOM) are proposed for assessing the efficiency and LMF performance of the coil assemblies. The target application is electric vehicle inductive chargers where the LMF is suppressed via passive shielding. The impact of the coil assembly’s geometric parameters on both FOMs is examined through a combination of finite element analysis (FEA) simulation and magnetic circuit analysis, and measures to improve the FOMs are studied Optimization of an exemplary coil assembly within given dimensional limits is conducted and the performance improvement is verified by FEA simulation results. <br>

scholarly journals Simulation and Analysis of Fluid-Solid Coupling of Wave Impact Sandcastle Based on COMSOL

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Zhen Ouyang ◽  
Ke Wang ◽  
Zihao Yu ◽  
Kaikai Xu ◽  
Qianyu Zhao ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Simulation Analysis ◽  
Coupling Model ◽  
Complex Problem ◽  
Wave Impact ◽  
Element Analysis ◽  
Quantitative Calculation ◽  
The Finite Element Analysis ◽  
The Impact

It is a complex problem to study the interaction between sand castle and flowing water, which needs to consider the complexity of seawater flow and the stress of sand castle structure. The authors use the fluid-solid coupling model to establish the connection between the fluid field and the structural mechanical field, and use the finite element analysis to complete the simulation modeling of the transient process of wave impact and sandcastle foundation deformation. This paper analyzes the stress and the first principal strain of the sand castle foundation in the direction of flow velocity when the sand castle foundation is hit by waves, as a method to judge the strength of the sand castle.The best shape: the boundary value of sand castle collapse caused by strain have been determined, so as to obtain the maximum stress that a sand castle foundation can bear before collapse, which makes it possible to use the fatigue strength calculation theory of sand castle solid to carry out the quantitative calculation of sand castle durability. At the same time, the impact of waves is abstracted as wave motion equation. Finally, the finite element analysis technology is adopted to calculate the main strain of sandcastles of different shapes under the impact of the same wave, and through the comparison of the main strain, the authors get the sandcastle shape with the strongest anti-wave impact ability, which is the eccentric circular platform body.Affected by rain: the authors considered the effect of rainwater infiltration on the sandcastle's stress, and simplified the process of rain as a continuous and uniform infiltration of rain into the sandcastle's surface. The rain changes the gravity of the sand on the castle's surface. Simulation analysis is adopted to calculate the surface stress of sand castle with different degree of water seepage and different geometry. By comparison, it has been found that the smooth cone is more able to withstand the infiltration of rain without collapse. 

Finite Element Analysis for Shock Resistance Evaluation of Cushion-Packaged Multifunction Printer Considering Internal Modules

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Se-Chang Kim ◽  
Dae-Geun Cho ◽  
Tae-Gyu Kim ◽  
Se-Hun Jung ◽  
Ja-Choon Koo ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shock Acceleration ◽  
External Shocks ◽  
Compression Tests ◽  
Element Analysis ◽  
Dynamic Behaviors ◽  
Shock Resistance ◽  
The Impact ◽  
Multifunction Printer

Failures in IT electronics are often caused by falling or external shocks during transportation. These failures cause customers to mistrust the reliability of the products. Many manufacturers of IT electronics have not only used cushioning materials but also increased the shock resistance of their products for failure prevention. Especially in case of printer products, the design of the packaging and the product robustness are extremely important because of their substantial weight and the fragility of the internal modules. For product design, it is essential to understand the impact failure mechanism of the products. In this study, a compression test, a drop impact test, and a finite element analysis (FEA) were performed to analyze the dynamic behaviors of a packaged multifunction printer (MFP). The mechanical properties of a cushioning material were measured by compression tests. The FE models of the cushion packaging and the MFP included the physical characteristics of the internal modules, and their dynamic behaviors were obtained using the commercial software ls-dyna3d. Simulation results were also compared with drop test results to verify the proposed FE models. The shock resistance of the MFP was assessed by stress analysis and strength evaluation. We also expect our FE models will be useful for evaluating the fragility of the internal modules because the models can numerically estimate the shock acceleration profiles of the internal modules, which are difficult to measure experimentally.

scholarly journals Finite Element Analysis Of Airfield Flexible Pavement

2014 ◽  
Vol 60 (3) ◽  
pp. 323-334 ◽  
Author(s):  
G. Leonardi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
3D Model ◽  
Numerical Study ◽  
Permanent Deformation ◽  
Flexible Pavement ◽  
Finite Element Code ◽  
Element Analysis ◽  
Pavement Response ◽  
The Impact

Abstract The paper presents a numerical study of an aircraft wheel impacting on a flexible landing surface. The proposed 3D model simulates the behaviour of flexible runway pavement during the landing phase. This model was implemented in a finite element code in order to investigate the impact of repeated cycles of loads on pavement response. In the model, a multi-layer pavement structure was considered. In addition, the asphalt layer (HMA) was assumed to follow a viscoelastoplastic behaviour. The results demonstrate the capability of the model in predicting the permanent deformation distribution in the asphalt layer.

Low-velocity impact properties and finite element analysis of syntactic foam reinforced by warp-knitted spacer fabric

2016 ◽  
Vol 87 (16) ◽  
pp. 1938-1952 ◽  
Author(s):  
Chao Zhi ◽  
Hairu Long ◽  
Fengxin Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Syntactic Foam ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Element Analysis ◽  
Velocity Impact ◽  
Impact Performance ◽  
Spacer Fabric ◽  
The Impact

The aim of this research was to investigate the low-velocity impact properties of syntactic foam reinforced by warp-knitted spacer fabric (SF-WKSF). In order to discuss the effect of warp-knitted spacer fabric (WKSF) and hollow glass microballoon parameters on the impact performance of composites, eight different kinds of SF-WKSF samples were fabricated, including different WKSF surface layer structures, different spacer yarn diameters and inclination-angles, different microballoon types and contents. The low-velocity impact tests were carried out on an INSTRON 9250 HV drop-weight impact tester and the impact resistances of SF-WKSF were analyzed; it is indicated that most SF-WKSF specimens show higher peak impact force and major damage energy compared to neat syntactic foam. The results also demonstrate that the surface layer structure, inclination-angle of the spacer yarn and the volume fraction and type of microballoon have a significant influence on the low-impact performance of SF-WKSF. In addition, a finite element analysis finished with ANSYS/LS-DYNA and LS-PrePost was used to simulate the impact behaviors of SF-WKSF. The results of the finite element analysis are in agreement with the experimental results.

Finite Element Analysis of Creep Behavior of AZ91D Magnesium Matrix Composites Reinforced with Aluminum Silicate Short Fibers

2012 ◽  
Vol 568 ◽  
pp. 311-314
Author(s):  
Jun Tian ◽  
Shou Yan Zhong ◽  
Zi Qiong Shi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Creep Rate ◽  
Creep Behavior ◽  
Axial Stress ◽  
Short Fiber ◽  
Steady Creep ◽  
Element Analysis ◽  
Interface Module ◽  
The Impact

By Computer finite element analysis, the impact of the interface thickness, the interface module and the short fiber orientation of Al2O3-SiO2(sf)/AZ91D composite on the maximum fiber axial stress and the steady creep rate is studied. Maximum axial stress of the short fiber is in the fiber center, and the axial stress gradually decreases along the direction of the fiber length. When the external stress is constant, the maximum fiber axial stress increases with decreasing of the thickness of the interface, and the steady creep rate increases with the increasing of thickness of the interface. The maximum fiber axial stress increases with the increasing of the interface modulus, the increasing of the interface module improves the load transfer and the creep resistance. Finite element simulation results and experimental results can be well matched to better explain the creep behavior.

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