Flexibility Analysis

2021 ◽  
pp. 75-87
Author(s):  
Charles Becht
Keyword(s):  
Stress Analysis ◽  
Analysis Model ◽  
Flexibility Analysis ◽  
Beam Analysis

Piping flexibility analysis is also known as piping stress analysis. Neither phrase satisfactorily describes all that is involved in this piping design discipline. In flexibility analysis, the response of the system to loads is calculated. The objectives of flexibility analysis are to calculate stress in the pipe; loads on supports, restraints, and equipment; and displacement of the pipe. It is essentially a beam analysis model on pipe centerlines. The fundamental principles include the following:

A Study on Development of Optimum FE Analysis Model on Welding Stress Analysis for CEDM Penetration Nozzle

2014 ◽  
Author(s):  
Tae-young Ryu ◽  
J. B. Choi ◽  
Kyoung S. Lee
Keyword(s):  
Residual Stress ◽  
Stress Analysis ◽  
Experimental Methods ◽  
Fe Analysis ◽  
Welding Residual Stress ◽  
Hole Drilling ◽  
Fe Model ◽  
Analysis Model ◽  
Welding Stress ◽  
Mesh Density

For decades, the PWSCC on the penetration nozzles like BMI and CEDM nozzles are widely occurred all around the world. The PWSCC is dependent on the tensile stress condition, specific materials and chemical environment. Therefore, to evaluate the severity of the PWSCC, prediction of the welding residual stress on the J-groove welding part in the penetration nozzles is essential. Residual stress can be measured by using experimental methods like deep-hole drilling and X-ray diffraction, etc. However, the results of experimental methods are quite doubtable and these methods are hard to apply on the actual equipment. Therefore, computational approach like the FE analysis has been considered. The FE analysis results are very sensitive to the FE model density and analysis conditions. In this paper the optimized FE model for the residual stress analysis will be developed in the case of CEDM penetration nozzle. The optimized parameters contains bead number and mesh density. The bead numbers along the longitudinal and circumferential directions are considered and the mesh density in each the bead is also considered. The model will be verified by numerical error control.

The Advantage of Using a File Data Transfer Method in a Plant Design

2014 ◽  
Author(s):  
Michael Fung ◽  
Andy Fung ◽  
Richard H. Fung ◽  
P. K. Fung
Keyword(s):  
Structural Analysis ◽  
Stress Analysis ◽  
Data Transfer ◽  
Support Vector ◽  
Petrochemical Plant ◽  
Plant Design ◽  
Analysis Program ◽  
Analysis Model ◽  
Design Information ◽  
Transfer Method

In general, there are two methods to pass on design information in a petrochemical plant design: the manual data key-in method and the file data transfer method. The manual data key-in method is a basic method to pass on data; but this method is time consuming to assign data in one by one fashion. The file data transfer method is a mapping file data from one program to another program under certain specific function and criteria. This paper starts with how to use a file data transfer method to create a stress analysis model, and then proposes an approach to transfer the stress analysis result to a structural analysis program by using the Pipe Loadings Transfer Program. In a piping design using 3D plant design software for modeling, the piping design information can be directly transferred to the stress input file by using point vectors to create a stress analysis model. The concepts of a pipe support vector and a beam vector were introduced to transfer the pipe loadings from stress analysis results to a structural analysis program. The advantages of using a file data transfer method are simple, fast, and accurate.

The Surge Line Stress Analysis Model Setup With the Consideration of Thermal Stratification

2014 ◽  
Author(s):  
Jianjun Wang ◽  
Zengfang Ge ◽  
Zhongning Sun ◽  
Changqi Yan
Keyword(s):  
Stress Analysis ◽  
Transient Process ◽  
Thermal Stratification ◽  
Nuclear Power ◽  
Transient Temperature ◽  
Analysis Model ◽  
Pressurized Water ◽  
Line Model ◽  
Transient Temperature Distribution ◽  
Surge Line

In this paper, we deal with a typical pressurizer surge line in a conventional pressurized water reactor (PWR). This study is performed to develop an understanding of thermal stratification phenomenon, which may occur in the surge line during either normal condition or transient process, in the pressurizer surge line. The pressurizer surge line model of Daya Bay nuclear power plant is used as base analysis model, in which the hot leg is taken into account. The transient temperature distribution required to assess the phenomenon along the pressurizer surge line is obtained through CFD analysis technology using ANSYS FLUENT. The temperature loads are transferred to ANSYS Mechanical for stress evaluation for the heat up transient process. Subsequently, the usage factor is calculated on the basis of ASME Section-III design curve. The possible mitigation scheme for the thermal stratification phenomenon of changing the layout angles is also simulated and analyzed in detail. The results show that the thermal stratification phenomenon will occur both in normal operating condition and in heat up transient process. The circumfluent effect makes the thermal stratification phenomenon exhibit unique profile due to the introduction of the hot leg. The continuous spray mass flow rate may influence both the temperature difference and the occurrence range for the thermal stratification phenomenon. The stress analysis incorporating both temperature load and pressure load is performed for pressurizer surge line model with hot leg for the conservative and complete heat up case.

Stress Relief in Solder Joints Due to the Application of a Flex Circuit

1991 ◽  
Vol 113 (3) ◽  
pp. 240-243 ◽  
Author(s):  
E. Suhir
Keyword(s):  
Fatigue Life ◽  
Stress Analysis ◽  
Solder Joints ◽  
Stress Relief ◽  
Physical Design ◽  
Thermal Contraction ◽  
Analysis Model ◽  
Rigid Substrate

A stress analysis model is developed to assess the stresses in solder joints caused by thermal contraction mismatch between a low expansion flex-circuit (FC) and a high expansion rigid substrate. It is shown that application of low expansion FCs can result in significant stress relief for solder joints. This is due to the fact that the force acting on a joint cannot exceed the buckling force for the adjacent portion of the FC. It is shown that the strains in solder joints interconnecting FCs to rigid substrates can be made very small, thereby resulting in a substantially longer fatigue life of the interconnection. In the executed example these strains are about two orders of magnitude smaller, than in the case of a rigid board. The obtained results can be utilized as guidance in physical design of assemblies with FCs.

Thermomechanical Durability Analysis of Flip Chip Solder Interconnects: Part 1—Without Underfill

1999 ◽  
Vol 121 (4) ◽  
pp. 231-236 ◽  
Author(s):  
K. Darbha ◽  
J. H. Okura ◽  
A. Dasgupta
Keyword(s):  
Stress Analysis ◽  
Flip Chip ◽  
Thermal Loading ◽  
Damage Model ◽  
Element Model ◽  
Analysis Model ◽  
Solder Interconnects ◽  
Durability Analysis ◽  
Adequate Accuracy ◽  
Fatigue Endurance

A generalized multi-domain Rayleigh-Ritz (MDRR) approach developed by Ling and Dasgupta (1995), is extended in this paper, to obtain the stress field in flip chip solder interconnects, under cyclic thermal loading. Elastic, Plastic and time-dependent visco-plastic analysis is demonstrated on flip chip solder interconnects. The method has been applied to other surface-mount interconnects in the past such as J-lead (Ling and Dasgupta, 1996a) and ball-grid joints (Ling and Dasgupta, 1997). The analysis results for the J-lead and ball grid joints have confirmed that the MDRR technique is capable of providing stress-strain hysteresis with adequate accuracy, at a fraction of the modeling effort required for finite element model generation and analyses. Nonlinear viscoplastic stress analysis results for flip chip interconnects without underfill are presented in this paper. The fatigue endurance of the solder joints is assessed by combining results from this stress analysis model with an energy-partitioning damage model (Dasgupta et al., 1992). The life predicted by the analytical damage model is compared with experimental results.

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