Lateral Loading of Internally Pressurized Steel Pipes

2005 ◽  
Author(s):  
S. A. Karamanos ◽  
K. P. Andreadakis ◽  
A. M. Gresnigt
Keyword(s):  
Internal Pressure ◽  
Test Results ◽  
Steel Pipes ◽  
End Conditions ◽  
Pressure Tubes ◽  
Nonlinear Shell ◽  
Numerical Tools ◽  
Model Equations ◽  
Device Size ◽  
Good Agreement

The paper examines the denting response of tubular members and pipes subjected to lateral (transverse) quasi-static loading, in the presence of internal pressure. Tubes are modeled with nonlinear shell finite elements, and the numerical results are in good agreement with available experimental data. Using the numerical tools, a parametric study is conducted to examine the effects of pressure level, as well as those of denting device size and pipe end conditions. It is mainly concluded that for a given denting displacement, the presence of internal pressure increases significantly the corresponding denting force. A simplified two-dimensional heuristic model is also adopted, which yields closed-form expressions for the denting force. The model equations are in fairly good agreement with the test results and illustrate pipe denting response in an elegant manner.

Lateral Loading of Internally Pressurized Steel Pipes

2006 ◽  
Vol 129 (4) ◽  
pp. 630-638 ◽  
Author(s):  
Arnold M. Gresnigt ◽  
Spyros A. Karamanos ◽  
Kyros P. Andreadakis
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Internal Pressure ◽  
Lateral Loading ◽  
Two Dimensional ◽  
Heuristic Model ◽  
Steel Pipes ◽  
Nonlinear Shell ◽  
Model Equations ◽  
Good Agreement

This paper examines the denting response of pipes subjected to lateral (transverse) quasistatic wedge loading, in the presence of internal pressure. Pipes are modeled with nonlinear shell finite elements and a simplified analytical model. The analysis focuses on the significant influence of internal pressure on the denting resistance. Furthermore, the effects of wedge denting device orientation on the denting resistance are briefly discussed. Motivated by the experimental and numerical results, a two-dimensional heuristic model is proposed, which yields closed-form expressions for the denting force in terms of the corresponding displacement. The finite element results and the model equations are in good agreement with the experimental results and illustrate pipe denting response in an elegant manner.

Experimental and Numerical Analysis of Ratcheting Behavior of SS 316 L Thin-Walled Pipes Subjected to Cyclic Internal Pressure

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
R. Karimi ◽  
M. Shariati
Keyword(s):  
Internal Pressure ◽  
Kinematic Hardening ◽  
Pressure Amplitude ◽  
Steel Pipes ◽  
Ratcheting Strain ◽  
Mean Pressure ◽  
Thin Walled Pipe ◽  
Thin Walled ◽  
Hoop Direction ◽  
Good Agreement

Abstract This paper investigates ratcheting behavior of SS316 L thin-walled steel pipes subjected to cyclic internal pressure experimentally and numerically. Numerical simulations were performed using abaqus software, and nonlinear isotropic/kinematic hardening model. According to experimentations, it was found that the ratcheting strain is only significant in the hoop direction of a pipe subjected to cyclic internal pressure. The effects of pressure amplitude and mean pressure on ratcheting behavior of thin walled pipe in hoop direction were studied experimentally and numerically, and it was observed that increasing the pressure amplitude and mean pressure increased the percentage of ratcheting strain. Another important point about the results was the dominance of pressure amplitude on mean pressure. The results showed that at higher mean pressures the effect of pressure amplitude on increasing the percentage of ratcheting strain was greater. Finally, the experimental and numerical results were in good agreement.

Comparison of Numerical Models and Verification Against Experimental Data, Using Pelastar TLP Concept

2015 ◽  
Author(s):  
Luca Vita ◽  
G. K. V. Ramachandran ◽  
Antonia Krieger ◽  
Marit I. Kvittem ◽  
Daniel Merino ◽  
...  
Keyword(s):  
Experimental Data ◽  
Numerical Solutions ◽  
Numerical Models ◽  
Complex Problem ◽  
Ocean Basin ◽  
Irregular Waves ◽  
Test Results ◽  
Regular Waves ◽  
Numerical Tools ◽  
Good Agreement

The analysis of a FWT is a complex problem, which requires advanced tools. Several numerical solutions have been used to couple hydrodynamics and aerodynamics and some of the available numerical tools have been compared in code-to-code comparisons. However the code validation for analysis of FWTs is limited by the number of available experimental data. In the present article, DNV GL and Glosten present a code comparison of four numerical tools against model test results. The design used for the analysis is the Pelastar Tension Leg Platform (TLP) by Glosten. A 1/50 downscaled model of the platform and NREL-5 MW wind turbine was tested in MARIN ocean basin. The results from the model tests are used to verify the results from the numerical codes. The FWT is modelled using four different codes: HAWC2 (by DTU and used by DNV GL), BLADED (by DNV GL and used by DNV GL), SIMA (by Marintek and used by DNV GL) and ORCAFLEX (by Orcina and used by Glosten). Although differences exist among these codes, comparable approaches have been used. Results from the numerical codes are compared against the experimental data, in terms of: - Natural periods - Response in regular waves - Response in irregular waves - Response in irregular waves with aerodynamic loads. In general, the results show a good agreement between the different numerical models and all the codes are capable to reproduce the main dynamics of the system. Some deviations were found and should be solved, in order to use these models for a detailed analysis. However these differences do not seem to be due to limitations of the codes and they might be solvable with a more accurate model of the system.

Pipe Response Under Concentrated Lateral Loads and External Pressure

2006 ◽  
Author(s):  
Kyros P. Andreadakis ◽  
Spyros A. Karamanos
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Three Dimensional ◽  
External Pressure ◽  
Pressure Effects ◽  
Lateral Loads ◽  
End Conditions ◽  
Different Types ◽  
Different Levels ◽  
Good Agreement

The paper focuses on the denting the response of pipeline segments subjected to lateral quasi-static wedge loading, in the presence of internal pressure. Nonlinear finite element models of pipeline segments, which are in good agreement with denting test data from internally pressurized pipes, are employed to obtain load-deflection curves for different levels of pressure, for various wedge shapes and for different types of boundary conditions. It is found that the presence of internal pressure increases significantly the denting resistance. The present study gives special emphasis on the development of a simplified three-dimensional analytical model, which yields closed-form expressions for the denting force and the corresponding denting length in terms of the corresponding denting displacement. The model, introduced elsewhere for non-pressurized tubes, is enhanced to include the pressure effects, accounting for different types of pipe end conditions. The analytical solution compares very well with the finite element results, and illustrates tube denting response in a clear and elegant manner.

Effect of design parameters on stresses occurring at the tooth root in a spur gear pressed on a shaft

2021 ◽  
pp. 095440892199529
Author(s):  
Fatih Güven
Keyword(s):  
Internal Pressure ◽  
Tangential Stress ◽  
Spur Gear ◽  
Design Parameters ◽  
Interference Fit ◽  
Gear Design ◽  
Compact Design ◽  
Fit Tolerance ◽  
Moderate Stress ◽  
Good Agreement

Gears are commonly used in transmission systems to adjust velocity and torque. An integral gear or an interference fit could be used in a gearbox. Integral gears are mostly preferred as driving gear for a compact design to reduce the weight of the system. Interference fit makes the replacement of damaged gear possible and re-use of the shaft compared to the integral shaft. However, internal pressure occurs between mating surfaces of the components mated. This internal pressure affects the stress distribution at the root and bottom land of the gear. In this case, gear parameters should be re-considered to assure gear life while reducing the size of the gear. In this study, interference fitted gear-shaft assembly was examined numerically. The effects of rim thickness, profile shifting, module and fit tolerance on bending stress occurring at the root of the gear were investigated to optimize gear design parameters. Finite element models were in good agreement with analytical solutions. Results showed that the rim thickness of the gear is the main parameter in terms of tangential stress occurring at the bottom land of the gear. Positive profile shifting reduces the tangential stress while the pitch diameter of the gear remains constant. Also, lower tolerance class could be selected to moderate stress for small rim thickness.

scholarly journals Spine Examination during COVID-19 Pandemic via Video Consultation

2021 ◽  
Author(s):  
Tom Jansen ◽  
Martin Gathen ◽  
Amadeo Touet ◽  
Hans Goost ◽  
Dieter Christian Wirtz ◽  
...  
Keyword(s):  
Pain Intensity ◽  
Range Of Motion ◽  
Test Results ◽  
Risk Of Infection ◽  
Face To Face ◽  
Reliable Tool ◽  
Provocation Tests ◽  
Active Range Of Motion ◽  
Video Consultation ◽  
Good Agreement

Abstract Introduction During the current COVID-19 pandemic video consultations are increasingly common in order to minimize the risk of infection for staff and patients. The aim of this study was to evaluate the feasibility of a spine examination via video. Methods A total of 43 patients were recruited. Each participant underwent a video-based (VB) and a conventional face-to-face (FTF) spine examination. Pain intensity, active range of motion, inspection, a neurophysiologic basic exam and provocations tests were evaluated using video-based and face-to-face methods. Results The intra-rater reliability (IRR) was measured between both examinations. Good to very good IRR values were obtained in inspection (Kappa between 0,752 und 0,944), active range of motion and basic neurophysiological examination (Kappa between 0,659 und 0,969). Only moderate matches were found in specific provocation tests (Kappa between 0,407 und 0,938). A video-based spine examination is a reliable tool for measuring pain intensity, active range of motion and a basic neurophysiologic exam. Conclusion A basic spine examination during a video consultation is possible. A good agreement of the test results between video-based and face-to-face examination could be found.

Design of combined brake system for light weight scooters

2021 ◽  
pp. 095440702110240
Author(s):  
Yuan-Ting Lin ◽  
Chyuan-Yow Tseng ◽  
Jao-Hwa Kuang ◽  
Yeong-Maw Hwang
Keyword(s):  
Ride Comfort ◽  
Brake System ◽  
Force Distribution ◽  
Test Results ◽  
Systematic Method ◽  
Braking Performance ◽  
Evaluation Indexes ◽  
Low Costs ◽  
Braking Force ◽  
Good Agreement

The combined brake system (CBS) is a mechanism that links the front and rear brakes for scooters. For two-wheeled scooters, a CBS with appropriate braking force distribution can reduce the risk of crashing accidents due to insufficient driving proficiency. The design of the braking force distribution for a CBS is challenging to the designer because it has to fulfill many requirements such as braking performance, ride comfort, reliability, and low costs. This paper proposes a systematic method to optimize the parameters of CBS. The evaluation indexes for the design are first discussed. The steps to determine the critical parameter to meet the indexes and a method to predict braking performance are developed. Finally, driving tests are carried out to verify the effectiveness of the proposed method. Experimental results showed that the deceleration of the tested scooter equipped with the designed CBS achieves an average mean fully developed deceleration (MFDD) of 5.246 m/s2, higher than the homologation requirement. Furthermore, the proposed method’s prediction of braking performance is in good agreement with the test results, with errors <1%.

Study on the stiffness degradation in concrete continuous beam with externally prestressed CFRP tendons under fatigue loading

2021 ◽  
pp. 136943322199249
Author(s):  
Xing Li ◽  
Jiwen Zhang ◽  
Jun Cheng
Keyword(s):  
Fatigue Life ◽  
Fatigue Loading ◽  
Load Level ◽  
Fiber Reinforced Polymer ◽  
Stiffness Degradation ◽  
Test Results ◽  
Reinforced Polymer ◽  
Continuous Beams ◽  
Practical Engineering ◽  
Good Agreement

This paper presents fatigue behaviors and the stiffness degradation law of concrete continuous beams with external prestressed carbon fiber-reinforced polymer (CFRP) tendons. Three specimens were tested under fatigue loading, and the influence of different load levels on the stiffness degradation and fatigue life were studied, and it was found that the stiffness degradation of three test specimens exhibited a three-stage change rule, namely rapid decrease, stable degradation, and sharp decline, but there are obvious differences in the rate and amplitude of stiffness degradation. The load level has a significant influence on the fatigue life of the test specimens. An analytical model with load level considered was proposed to calculate the residual stiffness and predict the stiffness degradation, which is in good agreement with the test results. The model of stiffness degradation presents a possible solution for practical engineering applications of concrete continuous beams with externally prestressed CFRP tendons subjected to different fatigue loadings.

A Study on Estimation of Internal Pressure Creep Life Using Small Punch Creep (SPC) Tests for Boiler Pipes

2009 ◽  
Author(s):  
Toshimi Kobayashi ◽  
Toru Izaki ◽  
Junichi Kusumoto ◽  
Akihiro Kanaya
Keyword(s):  
Internal Pressure ◽  
Residual Life ◽  
Test Results ◽  
Creep Life ◽  
Creep Tests ◽  
Good Correspondence ◽  
Small Punch ◽  
Uniaxial Creep ◽  
Wide Range ◽  
The Relationship

The small punch creep (SPC) test is possible to predict residual creep life at a high accuracy. But, the results of SPC tests cannot be compared with uniaxial creep or internal pressure creep results directly. In this report, the relationship between SPC test results and uniaxial creep test results in ASME A335 P11 (1.25Cr-0.5Mo Steel) was studied. The obtained relationship between SPC load and equivalent uniaxial creep stress formed a simple linear equation under the wide range of test temperature and test period. Then, the SPC results can be compared with uniaxial results by converting SPC loads to the equivalent uniaxial creep stresses. The relationship between SPC test results and internal pressure creep tests results was also studied. The internal creep life of as-received P11 pipe was almost same as SPC result when the hoop stress was converted to the SPC load. The creep lives of internal pressure creep influenced materials also showed good correspondence with SPC results. Therefore SPC can estimate the residual life of internal pressure creep influenced materials.

Investigating the vibrational behaviour of a rotating two-blade propeller by using a self-tracking method

2018 ◽  
Vol 233 (3) ◽  
pp. 835-847 ◽  
Author(s):  
Mohammad-Reza Ashory ◽  
Farhad Talebi ◽  
Heydar R Ghadikolaei ◽  
Morad Karimpour
Keyword(s):  
Natural Frequency ◽  
Measurement Errors ◽  
Mode Shapes ◽  
Model Parameters ◽  
Test Results ◽  
Modal Assurance Criterion ◽  
Tracking Method ◽  
Strong Resemblance ◽  
Test Scenarios ◽  
Good Agreement

This study investigated the vibrational behaviour of a rotating two-blade propeller at different rotational speeds by using self-tracking laser Doppler vibrometry. Given that a self-tracking method necessitates the accurate adjustment of test setups to reduce measurement errors, a test table with sufficient rigidity was designed and built to enable the adjustment and repair of test components. The results of the self-tracking test on the rotating propeller indicated an increase in natural frequency and a decrease in the amplitude of normalized mode shapes as rotational speed increases. To assess the test results, a numerical model created in ABAQUS was used. The model parameters were tuned in such a way that the natural frequency and associated mode shapes were in good agreement with those derived using a hammer test on a stationary propeller. The mode shapes obtained from the hammer test and the numerical (ABAQUS) modelling were compared using the modal assurance criterion. The examination indicated a strong resemblance between the hammer test results and the numerical findings. Hence, the model can be employed to determine the other mechanical properties of two-blade propellers in test scenarios.

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