Weak-Link Analysis of Motor-Operated Butterfly Valve

2002 ◽  
Author(s):  
Donghae Kim
Keyword(s):  
Structural Integrity ◽  
Weak Link ◽  
Link Analysis ◽  
Seismic Load ◽  
Seismic Loads ◽  
Static Force ◽  
Bending Stress ◽  
Butterfly Valve ◽  
Load Path ◽  
Valve Assembly

The purpose of this paper is to address the structural integrity of the motor operated butterfly valve assembly by providing the methodology and equations to quantitatively determine the permissible component load in the load path from the operator to the valve. The weak link analysis is to determine the maximum allowable torque on the butterfly valve by equating the stresses caused by the torque and seismic load with the appropriate allowable stress value, and then the unknown torque is solved. Analysis methods are based on classical static force balancing equations and on classical axial, shear, and bending stress equations using the worst possible load combinations including seismic loads resulting from design basis earthquake.

Character Analysis of Balance and Imbalance of Varying Rigidity of Rigid Pile Composite Foundation under Seismic Load

2014 ◽  
Vol 1065-1069 ◽  
pp. 19-22
Author(s):  
Zhen Feng Wang ◽  
Ke Sheng Ma
Keyword(s):  
Finite Element ◽  
Bending Moment ◽  
Horizontal Displacement ◽  
Element Model ◽  
Composite Foundation ◽  
Seismic Load ◽  
Seismic Loads ◽  
Element Analysis ◽  
Rigid Pile ◽  
Rigid Pile Composite Foundation

Based on ABAQUS finite element analysis software simulation, the finite element model for dynamic analysis of rigid pile composite foundation and superstructure interaction system is established, which selects the two kinds of models, by simulating the soil dynamic constitutive model, selecting appropriate artificial boundary.The influence of rigid pile composite foundation on balance and imbalance of varying rigidity is analyzed under seismic loads. The result shows that the maximum bending moment and the horizontal displacement of the long pile is much greater than that of the short pile under seismic loads, the long pile of bending moment is larger in the position of stiffness change. By constrast, under the same economic condition, the aseismic performance of of rigid pile composite foundation on balance of varying rigidity is better than that of rigid pile composite foundation on imbalance of varying rigidity.

Nanovoid Formation at Cu/Cu/Cu Interconnections of Blind Microvias: A Field Study

2019 ◽  
Vol 2019 (1) ◽  
pp. 000492-000502 ◽  
Author(s):  
T. Bernhard ◽  
L. Gregoriades ◽  
S. Branagan ◽  
L. Stamp ◽  
E. Steinhäuser ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Structural Integrity ◽  
Weak Link ◽  
Critical Factor ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Different Types ◽  
Key Factor ◽  
Electrical Reliability ◽  
The Impact

Abstract A key factor for a high electrical reliability of multilayer High Density Interconnection Printed Circuit Boards (HDI PCBs) is the thermomechanical stability of stacked microvia interconnections. With decreasing via sizes and higher numbers of interconnected layers, the structural integrity of these interconnections becomes a critical factor and is a topic of high interest in current research. The formation of nanovoids and inhibited Cu recrystallization across the interfaces are the two main indications of a weak link from the target pad to the filled via. Based on TEM/EDX measurements on a statistically relevant number of stacked and blind microvias produced in the industrial field, different types of nanovoid phenomena are revealed at the Cu/Cu/Cu junction. The types of nanovoids were categorized relating to the time of appearance (before or after thermal treatment), the affected interfaces or layers and the impact on the Cu recrystallization. The main root causes for each void type are identified and the expected impact on the thermomechanical stability of the via junction is discussed.

Finite Element Analyses of a Butterfly Valve Assembly

1989 ◽  
Vol 111 (2) ◽  
pp. 197-202
Author(s):  
B. Goksel ◽  
J. J. Rencis ◽  
M. Noori
Keyword(s):  
Finite Element ◽  
Fluid Pressure ◽  
Three Dimensional ◽  
Finite Element Analyses ◽  
Butterfly Valve ◽  
Commercial Code ◽  
Valve Assembly ◽  
Dimensional Finite Element ◽  
Static Fluid ◽  
Three Dimensional Finite Element

Two and three-dimensional finite element analyses of a butterfly valve assembly subjected to static fluid pressure were carried out using commercial code ANSYS. Good agreement between the experimental and finite element results were obtained. Sensitivity of results to various boundary and loading conditions was also investigated.

Challenges in Circumferential Entry Blades for Structural Integrity of Closing Blade in Steam Turbines

2018 ◽  
Vol 8 (3) ◽  
Author(s):  
A. S. SureshBabu ◽  
Jeevan Gowda G ◽  
M. V. Reddy
Keyword(s):  
Service Life ◽  
Structural Integrity ◽  
Weak Link ◽  
Kinematic Hardening ◽  
Research Work ◽  
Service Condition ◽  
Material Model ◽  
Steam Turbines ◽  
Mechanical Integrity ◽  
Locking Mechanism

The bladed disc of an LP last stage rotor assembly in a steam turbine often employs circumferential entry blades. The closing blade is fastened with the aid of a pin type locking mechanism, which locks the closing blade onto the disc. Radial entry blade root design demands for a groove in the disc through which blades are inserted and guided to their respective final positions which alters the stiffness in the disc. Closing blade is the most highly stressed weak link zone in the circumferential entry rotor disc achieving mechanical integrity for in-service condition is a challenge. Location of pin and its insertion is the key to achieve the desired in-service life with good material model. The present research work focus on emphasis of pin positioning to lock the T-root blade at operating range. Various material model configurations and pin positions are considered in both blade and disc to improve the reliability in design. Customized methodology is developed to address the elasto-plastic kinematic hardening in pin, disc and blade grove during in-service life. Finite element approach along with classical design equations followed by API 616 standards is employed to achieve the mechanical integrity in bladed disc assembly.

Monitoring Axial Strain in Synthetic Fiber Mooring Ropes Using Polymeric Optical Fibers

2003 ◽  
Author(s):  
D. Barton Smith ◽  
Jerry G. Williams
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Structural Integrity ◽  
Axial Strain ◽  
Time Domain Reflectometry ◽  
Synthetic Fiber ◽  
Load Path ◽  
Integrity Test ◽  
Reliable Technique ◽  
Polymeric Optical Fibers

Synthetic fiber ropes constructed of polyester are providing an important new technology for mooring deep-water drilling and production platforms. Considerable effort is being directed toward advancing and qualifying this enabling and cost-effective technology. To date, synthetic fiber mooring ropes have been successfully deployed in Brazil and they have seen limited service in the Gulf of Mexico. Synthetic fiber mooring ropes have high strength-to-weight ratios and possess adequate stiffness, but they are much more susceptible to damage than their steel counterparts. Future safe deployment of synthetic fiber mooring ropes would be significantly enhanced if a reliable technique were available to monitor the performance of the ropes in service and thus provide an early warning of the loss of structural integrity. Test data in the open literature indicates that the strain in the rope at failure is essentially a constant independent of load path or history. Measurement of the accumulated strain in the rope should thus provide a reliable benchmark with which to estimate the remaining life and establish criteria for rope recertification or retirement. This paper discusses the results of research and development activities aimed at developing a reliable, robust method for monitoring strain in braided and twisted strand Synthetic Fiber Mooring Ropes [1]. The strain transducer is a polymeric optical fiber, integrated into the mooring rope and interrogated with Optical Time-Domain Reflectometry (OTDR) to measure changes in its length as the optical fiber and rope are stressed. The method provides a direct measurement of large axial strains. Strains measured in polymeric optical fibers exhibit good one-to-one correlation with applied strains within the test range studied (10% or less, typically). The integrated polymeric optical fiber has been shown to withstand large numbers of repeated cycles to high strains without failure and to accurately track the hysteresis exhibited by polyester rope. Results are reported for tests conducted with polymeric optical fibers integrated into typical mooring rope elements.

scholarly journals Improved Tank Car Design Development: Ongoing Studies on Sandwich Structures

2009 ◽  
Author(s):  
David Y. Jeong ◽  
David C. Tyrell ◽  
Michael E. Carolan ◽  
A. Benjamin Perlman
Keyword(s):  
Engineering Design ◽  
Structural Integrity ◽  
Sandwich Structures ◽  
Hazardous Materials ◽  
Common Interest ◽  
Equal Weight ◽  
Load Path ◽  
Element Analysis ◽  
Design Studies ◽  
Design Requirements

The Government and industry have a common interest in improving the safety performance of railroad tank cars carrying hazardous materials. Research is ongoing to develop strategies to maintain the structural integrity of railroad tank cars carrying hazardous materials (hazmat) during collisions. This paper describes engineering studies on improved tank car concepts. The process used to formulate these concepts is based on a traditional mechanical engineering design approach. This approach includes initially defining the desired performance, developing strategies that are effective in meeting this performance, and developing the tactics for implementing the strategies. The tactics are embodied in the concept. The tactics and concept evolve through engineering design studies, until a design satisfying all of the design requirements is developed. Design requirements include service, manufacturing, maintenance, repair, and inspection requirements, as well as crashworthiness performance requirements. One of the concepts under development encases the pressurized commodity-carrying tank in a separate carbody. Moreover, this improved tank car concept treats the pressurized commodity-carrying tank as a protected entity. Welded steel sandwich structures are examined as a means to offer protection of the commodity tank against penetrations from impacting objects in the event of a collision. Sandwich structures can provide greater strength than solid plates of equal weight. Protection of the tank is realized through blunting of the impacting object and absorption of the collision energy. Blunting distributes impact loads over a larger area of the tank. Energy absorption reduces the demands on the commodity tank in the event of an impact. In addition, the exterior carbody structure made from sandwich panels is designed to take all of the in-service loads, removing the commodity tank from the load path during normal operations. Design studies described in this paper focus on the protection aspect of using sandwich structures. Studies are conducted to investigate the influence of different parameters, such as sandwich height and core geometry, on the force-deformation behavior of sandwich structures. Calculations are carried out numerically using nonlinear finite element analysis. These analyses are used to examine the crashworthiness performance of the conceptual design under generalized impact scenarios.

Effects of High Frequency Hydrodynamic Loads on Structural Integrity and Mechanical Operability of Valves

2015 ◽  
Author(s):  
Yigit Isbiliroglu ◽  
Cagri Ozgur ◽  
Evren Ulku ◽  
Nish Vaidya ◽  
Kristofor Paserba
Keyword(s):  
High Frequency ◽  
Structural Integrity ◽  
Energy Content ◽  
Hybrid Approach ◽  
Piping System ◽  
Seismic Loads ◽  
Damage Potential ◽  
Element Analysis ◽  
Piping Systems ◽  
Number Of Cycles

In-line valves are qualified for static as well as dynamic loads from seismic and hydrodynamic (HD) events. Seismic loads are generally characterized by frequency content less than about 33 Hz whereas HD loads may exhibit a broad range of frequencies greater than 33 Hz. HD loads may also result in spectral accelerations significantly in excess of those due to the design basis seismic events. Current regulatory guidelines do not specifically address the evaluation of equipment response to high frequency loading. This paper investigates the response of skid and line mounted valves of piping systems under HD loads by using several independent rigorous finite element analysis solutions for various piping system segments. It presents a hybrid approach for the evaluation of the response of valves to HD and seismic loads. The proposed approach significantly reduces the amount of individual analysis and testing needed to qualify the valves. First, valve responses are evaluated on the basis of displacements since HD loads are generally characterized by high frequencies and small durations. Second, the damage potential of the loads on the valve actuators is represented by the energy imparted to the actuator quantified in terms of Arias intensity. The rationale for using the energy content is based on the fact that damage due to dynamic loading is related not only to the amplitude of the acceleration response but also to the duration and the number of cycles over which this acceleration is imposed.

scholarly journals Seismic design of prestressed concrete buildings

1990 ◽  
Vol 23 (4) ◽  
pp. 288-304 ◽  
Author(s):  
Minehiro Nishiyama
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Dynamic Response ◽  
Seismic Design ◽  
Prestressed Concrete ◽  
Design Procedure ◽  
Seismic Load ◽  
Seismic Loads ◽  
Concrete Buildings ◽  
Reversed Cyclic

The current seismic design procedure for prestressed concrete buildings in Japan is described. The design seismic loads for prestressed concrete buildings provided in NZS 4203:1984 are compared with those in the corresponding Japanese code. Comparisons between prestressed concrete and ordinary reinforced concrete buildings are discussed with regard to design seismic load, dynamic response during earthquake motions and the performance of beam-column joints under reversed cyclic loading. The results of several tests are summarised.

scholarly journals Evaluation of notional loads magnitude to three calibration concentric braced frames subjected to seismic loads in Indonesia

2019 ◽  
Vol 276 ◽  
pp. 01005
Author(s):  
Heru Purnomo ◽  
Mulia Orientilize ◽  
Sjahril A Rahim ◽  
Firdaus A Zaki
Keyword(s):  
Numerical Study ◽  
Direct Analysis ◽  
Second Order ◽  
Effective Length ◽  
Seismic Load ◽  
Seismic Loads ◽  
Elastic Analysis ◽  
Braced Frames ◽  
Braced Frame ◽  
Geometric Imperfection

The changing of SNI 03-1729 from 2002 to 2015 which refer to AISC 2010 change the method of steel stability analysis from effective length method (ELM) to direct analysis method (DAM). DAM use second order elastic analysis, accommodate strength reduction, geometric imperfection presented as notional load, and take buckling factor (K) equal to 1. Numerical study has been conducted to find out the appropriate magnitude of notional loads on concentric braced frame subjected to seismic load in Indonesia. Experimental results from three different calibration frames from previous research were used as reference. The frames consisted of 1-story, 3-stories, and 5-stories were reanalyzed by using SAP software with four different methods: ELM first order elastic analysis, ELM second order elastic analysis, and DAM with different notional loads coefficient as 0.002 and 0.003. Seismic loads according SNI 1726:2012 in three seismic regions were considered.

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