The failure behavior of buckling pin valve: Theoretical, numerical, and experimental study

2022 ◽  
pp. 095440622110616
Author(s):  
Yanwen Zhang ◽  
Jiaqi Che ◽  
Changlu Yu ◽  
Hanxiang Wang ◽  
Mingchao Du
Keyword(s):  
Failure Load ◽  
Hydraulic Cylinder ◽  
Operational Reliability ◽  
Coal Bed ◽  
Failure Behavior ◽  
Relief Valve ◽  
Euler Formula ◽  
Low Concentration ◽  
Buckling Behavior ◽  
Explicit Dynamic

At present, buckling pin in the bypass of piping as pressure relief valve has been gradually utilized in the low-concentration coal-bed methane (CBM), which bends to release pressure when the main valve fails leading to pipeline blockage. However, current researches mainly focused on the buckling behavior of hydraulic cylinder rod or rod string, and less consideration was given to the operational reliability of buckling pin valves. This paper deduced the calculation formula of the critical failure load based on Euler formula in the buckling pin under buckling load. Besides, three finite element models (FEM) based on Johnson−Cook constitutive model were compared to predict failure strength of buckling pin which were verified by experiment. In addition, the defect sensitivity analysis of the buckling pin under different initial geometric defects rate was carried out. The results showed that a) the experimental value of the critical failure load in the buckling pin was 206.04 N and the bending position was in the middle of the buckling pin; b) the analysis result adopting explicit dynamic method was in best agreement with the experimental results within deviation of 0.24%; and c) the initial geometric defect of buckling pin should be controlled within 1%. This study provides an important reference to predict the critical failure load of the buckling pin valve and achieve safe transportation of low-concentration CBM.

scholarly journals Failure assessment of steel/CFRP double strap joints

2017 ◽  
Author(s):  
Hamid Reza Majidi ◽  
Seyed Mohammad Javad Razavi ◽  
Filippo Berto
Keyword(s):  
Failure Load ◽  
Steel Structures ◽  
Predictive Modelling ◽  
Failure Behavior ◽  
Static Tensile Loading ◽  
Failure Assessment ◽  
Theoretical Predictions ◽  
Static Tensile ◽  
Failure Loads ◽  
Good Agreement

In the current study, the failure behavior of retrofitted steel structures was studied experimentally and theoretically with steel/CFRP double strap joints (DSJs) under quasi-static tensile loading. A series of DSJs with different bonding lengths are also considered and examined to experimentally assess the effective bond length. To predict the failure load values of the tested specimens, a new stress-based criterion, namely the point stress (PS) criterion is proposed. Although some theoretical predictive modelling for the strength between steel/CFRP joints under various loading conditions has been presented, in this work by using the new proposed approach, one can calculate rapidly and conveniently the failure loads of the steel/CFRP specimens. Furthermore, to assess the validity of the new proposed criterion, further experimental data on steel/CFRP DSJs available in the open literature are predicted using the PS criterion. Finally, it was found that a good agreement exists between the experimental results and the theoretical predictions based on the PS criterion.

Effect of Piping System Vibration (FIV, AIV, PIV) on Pipe Support Loads

2021 ◽  
Author(s):  
Emmanuel Appiah ◽  
Phillip Wiseman
Keyword(s):  
Power Plants ◽  
Accurate Determination ◽  
Operational Reliability ◽  
Empirical Method ◽  
Piping System ◽  
Thin Wall ◽  
Relief Valve ◽  
Support Design ◽  
System Integrity ◽  
Vibration Loads

Abstract Integrity of a piping system is a prerequisite for personnel safety and operational reliability in industries where pipelines are critical means of transferring products from one process point to the other, such as power plants, refinery plants, and chemical industries. An essential aspect of designing a reliable piping system is to design supports of suitable load carrying capacity. This also depends on accurate determination of expected support loads including loads due to vibration of the system. Piping design codes such as ASME B31.3 and B31.1 provide a general framework but do not address vibration and its impact from a detailed perspective. In many situations, the potential impact of vibration is overlooked during support load determination. In recent piping system construction, the effect of vibration has increased due to increase in fluid flow rates and use of high strength thin wall materials. Common factors that contribute to vibration include: turbulent flow (flow induced vibration, FIV), relief valve operation (acoustic induced vibration, AIV), rotating and reciprocating equipment (pulsation induced vibrations, PIV). The effect of vibration depends on the strength of excitation and the flexibility of the piping system. As vibration of the piping system increases, loads transfer to the pipe supports also increase. Catastrophic failure of a piping system can occur if its natural frequency lock-in with the frequency of the excitation source. For holistic system integrity, the loads induced due to vibrations need to be accounted for in the support design. In this paper, we investigate the contributions of the various vibration loads in a piping system, the effect of neglecting the various vibration loads on the system integrity, and an empirical method to readily determine the vibration loads to reduce cost and time require in support design processes.

EFFECT OF TENSILE SPEED ON THE FAILURE LOAD OF A SPOT WELD UNDER COMBINED LOADING CONDITIONS

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1469-1474 ◽  
Author(s):  
JUNG-HAN SONG ◽  
HOON HUH ◽  
JI-HO LIM ◽  
SUNG-HO PARK
Keyword(s):  
Failure Load ◽  
Rate Sensitivity ◽  
Shear Loading ◽  
Spot Weld ◽  
Combined Loading ◽  
Failure Behavior ◽  
Loading Conditions ◽  
Dynamic Failure ◽  
Shear Loads ◽  
Failure Loads

This paper is concerned with the evaluation of the dynamic failure load of the spot weld under combined axial and shear loading conditions. The testing fixture are designed to impose the combined axial and shear load on the spot weld. Using the proposed testing fixtures and specimens, quasi-static and dynamic failure tests of the spot weld are conducted with seven different combined loading conditions. The failure load and failure behavior of the spot weld are investigated with different loading conditions. Dynamic effects on the failure load of the spot weld, which is critical for structural crashworthiness, are also examined based on the experimental data. In order to evaluate the effect of the strain rate on the failure contour of the spot weld under combined axial and shear loads, the failure loads measured from the experiment are decomposed into the two components along the axial and shear directions. Experimental results indicate that the failure contour is expanded with increasing strain rates according to the rate sensitivity of the ultimate stress for welded material.

Study Control System Based on Creep Test in High Density Baler

2010 ◽  
Vol 139-141 ◽  
pp. 1624-1627
Author(s):  
Wei Lee ◽  
Chun Guang Wang
Keyword(s):  
Control System ◽  
Data Acquisition ◽  
Creep Test ◽  
Hydraulic System ◽  
Electrical Contact ◽  
Hydraulic Cylinder ◽  
High Density ◽  
Hydraulic Control ◽  
Creep Tests ◽  
Relief Valve

Hydraulic transmission system controls hydraulic cylinder forward and backward movement freely, in order to achieve high density hydraulic baler work circulation. Creep test required hydraulic system to output constant stress, and study creep tests can not be completed when used succeeding the electrical contact style in the past time. The system used programmable logic controller (PLC) to instead of succeeding the electrical contact style and realized freely forward and backward movement of hydraulic cylinder, electro-hydraulic proportional relief valve can adjust hydraulic system and make it stepless pressure regulation and then degree of automation and reliability in hydraulic control system to be improved. This paper introduces aspects: including the selection, hardware configuration and program of PLC, meanwhile, giving specific realization method. Through the control system to study creep test in hydraulic baler, adopting the National Instrument (NI) company's multi-channel data acquisition card, which type is USB-6251,applying Labview8.2 to write data acquisition program on my own, the versatility and flexibility of system was verified, which was able to complete creep test successfully.

Numerical/Experimental Research on Welded Joints in Aluminium Truss Girders

2016 ◽  
Vol 710 ◽  
pp. 295-300
Author(s):  
Dianne van Hove ◽  
Frans Soetens
Keyword(s):  
Numerical Analysis ◽  
Failure Mode ◽  
Experimental Research ◽  
Welded Joints ◽  
Failure Load ◽  
Full Scale ◽  
Numerical Calculations ◽  
Failure Behavior ◽  
Design Rules ◽  
Steel Design

Welded joints in a 30 meter span aluminium truss girder were investigated numerically and experimentally. Since aluminium design rules for welded K-and N-joints in CHS truss girders were lacking the joints were checked using steel design rules. Calculations showed that the N-joints were governing for chord and brace sizes. Further numerical analysis on the N-joints using ANSYS 11.0 was carried out. Full scale experimental research was successfully carried out for validation of the numerical calculations. It is concluded that steel design rules predict the failure behavior and failure mode of the considered aluminium N-joints well. However, steel design rules overestimate the failure load by 8% for the truss configurations investigated.

scholarly journals Failure Strength of E-Glass/Epoxy Composite Pinned Joints: Effect of Geometry, Clamping Torque and Laminate Orientation

2007 ◽  
Vol 16 (3) ◽  
pp. 096369350701600 ◽  
Author(s):  
Yeliz Pekbey
Keyword(s):  
Composite Plate ◽  
Failure Modes ◽  
Failure Load ◽  
Epoxy Composite ◽  
Experimental Investigations ◽  
Failure Behavior ◽  
Displacement Curve ◽  
Failure Strength ◽  
Bearing Strength ◽  
Specimen Width

The experimental investigations described in this paper were conducted in order to study the strength and failure behavior of composite plate with pin-loaded conditions. The main objective of the present paper was to investigate the influence of certain factors on the strength of the pin-loaded in E-GLASS/EPOXY composite plate with different orientations such as [0/90/±30]s and [0/90/±60]s. These factors included the preload moment (M=0, 2 Nm), the ratio of the edge distance to the pin diameter ( E/ D), and the ratio of the specimen width to the pin diameter ( W/ D). The mechanical properties and failure strengths of E-GLASS/EPOXY composite were obtained with experimental measurements. Based on experiments, the effects of laminate orientation, and preload moment on joint strengths were systematically investigated. In addition, geometrical configurations of specimens were suitably varied in order to observe all possible failure modes. A total of 150 different pin-loaded composite plate specimens were tested under static loading conditions. The specimen tested exhibited different failure modes, consisting of bearing, net-tension and shear-out, depending on the geometry adopted. Guidelines for effective laminate orientations, geometrical configurations and preload moment for mechanically pin connected E-GLASS/EPOXY composite plate were specified based on ultimate bearing strength. From the experiments, it was also found that glass-epoxy with [0/90/±30]s yielded the highest bearing strengths. Bearing strengths reached when E/D and W/D ratios were equal or greater than 4 both [0/90/±30]s and [0/90/±60]s orientations. Besides, the experimental results showed that the load-displacement curve of specimen with M=0, had the lowest the failure strength. M=2Nm preload moment, had the maximum failure load.

A New Safety Enrichment Method for Low Concentration Coal Bed Methane-Proportion Pressure Swing Adsorption

2011 ◽  
Vol 233-235 ◽  
pp. 2276-2280 ◽  
Author(s):  
Yong Ling Li ◽  
Ying Shu Liu ◽  
Xiong Yang
Keyword(s):  
Pressure Swing Adsorption ◽  
Coal Bed ◽  
Coal Bed Methane ◽  
Carbon Molecular Sieve ◽  
Enrichment Method ◽  
Adsorption Characteristic ◽  
Low Concentration ◽  
Explosion Limit ◽  
Pressure Swing ◽  
Enrichment Process

Based on pressure swing adsorption, Proportion Pressure Swing Adsorption (PPSA), a new enrichment method with high safety, was suggested to enrich the low concentration coal bed gas. A mixture of active carbon (CA) and carbon molecular sieve (CMS) was employed as adsorbent in the process of PPSA. The methane and oxygen in coal bed gas were adsorbed simultaneously. The experimental study was carried out in order to verify the feasibility of this method. The equilibrium adsorption characteristic of CA and CMS were tested. The results showed that both concentrations of CH4 and O2 in desorption gas could be controlled well and would not exceed the explosion limit in enrichment process by adjusting the mass ratio of CMS5/AC1. Therefore, the new method, PPSA, can guarantee the safety in enrichment of coal bed methane.

scholarly journals Research on the position–pressure cooperative control strategy for full-hydraulic leveler

2018 ◽  
Vol 10 (12) ◽  
pp. 168781401881739
Author(s):  
Dongping He ◽  
Tao Wang ◽  
Jun Wang ◽  
Zhongkai Ren ◽  
Xiangyu Gao
Keyword(s):  
Control Strategy ◽  
Cooperative Control ◽  
High Speed ◽  
Servo System ◽  
Hydraulic Cylinder ◽  
Relief Valve ◽  
Working Pressure ◽  
Pressure Signal ◽  
Hydraulic Servo ◽  
Hydraulic Servo System

The characteristics of electro-hydraulic servo system of full-hydraulic leveler are high speed, large inertia, high frequency response, and multi-degree of freedom. In order to improve the degree of automation of full-hydraulic leveler and achieve the simultaneous control between position and pressure, the position–pressure cooperative control strategy is presented in the article. In the working process, the dynamic working pressure signal of the hydraulic cylinder is turned into a real-time position signal by the pressure–position conversion gain and then compensates the converted signal into the position closed loop. Meanwhile, the pressure signal of the rear cavity of the hydraulic cylinder is fed back to the input of the proportional relief valve at the pump source, and then the system work pressure changes quickly according to the different thickness. In this article, the mathematical model of position–pressure cooperative control of hydraulic straightening machine is established. The simulation results in AMESim software verify the correctness of the control strategy. Finally, the feasibility and practicability of the control strategy are verified by the field prototype of 11-roller full-hydraulic leveler. The control strategy provides the theoretical basis for designing the electro-hydraulic servo system.

Influence of the Geometric Imperfection on the Buckling Behavior of Floating Platform Column Under Axial Load

2007 ◽  
Author(s):  
Tiago P. Estefen ◽  
Daniel S. Werneck ◽  
Segen F. Estefen
Keyword(s):  
Progressive Failure ◽  
Correlation Study ◽  
Gas Production ◽  
Small Scale ◽  
Failure Behavior ◽  
Floating Platform ◽  
Cross Sectional ◽  
Geometric Imperfection ◽  
Stiffened Panels ◽  
Buckling Behavior

The present work focuses on the design of the new generation of semi-submersible platforms for oil&gas production offshore that is based on column square cross-sectional area. The platform column is based on an arrangement of stiffened flat panels having their ultimate strength characterized by buckling under in-plane compressive loading. Distortions induced by fabrication have considerable influence on the buckling behavior and are discussed in order to provide design recommendations. The aim of the paper is to study a segment of the column structural arrangement between robust transverse frames to analyze the failure behavior of the stiffened panels. Previous research demonstrated the strong influence of both mode and magnitude of the geometric imperfection distribution, as well as the boundary conditions. Numerical and experimental simulations for small scale isolated panels are carried out in order to perform a correlation study to adjust the numerical model for further use in more complex numerical simulations of the structural failure of the column arrangement. The stiffened panels are analyzed to identify the buckling initiation on a particular panel and then the interaction between plates, longitudinal stiffeners and the robust transverse frames during the progressive failure of the whole column.

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