Plastic Collapse Assessment Procedure for Vessel With Local Thin Area Simultaneously Subjected to Internal Pressure and External Bending Moment

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Shinji Konosu ◽  
Norihiko Mukaimachi
Keyword(s):  
Internal Pressure ◽  
Pressure Ratio ◽  
Bending Moment ◽  
Outer Diameter ◽  
Assessment Procedure ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Tension And Compression ◽  
And Storage ◽  
Moment Ratio Diagram

Assessment of the local thin area should be undertaken for both tension and compression bending. In this paper, simplified reference stresses for a flaw in a cylinder are proposed. By using these results, a newly developed p-M (internal pressure ratio and external bending moment ratio) diagram which can evaluate the collapse condition for pressure equipment such as vessels, piping, and storage tanks with a local thin area simultaneously subjected to internal pressure p and external bending moment M due to earthquake, etc., is proposed. The p-M line is verified by comparison with the finite element analysis results and the numerous results of experiment for a cylinder with a volumetric flaw obtained through the reference literatures. It was clarified that the differences in collapse limit between the p-M line and DNV guideline under both internal pressure and compression moment became evident where the outer diameter/wall thickness of a cylinder is large and the yield ratio of the material is small.

Plastic Collapse Assessment Procedure for Vessel With Local Thin Area Simultaneously Subjected to Internal Pressure and External Bending Moment

2006 ◽  
Author(s):  
Shinji Konosu ◽  
Norihiko Mukaimachi
Keyword(s):  
Internal Pressure ◽  
Pressure Ratio ◽  
Bending Moment ◽  
Outer Diameter ◽  
Assessment Procedure ◽  
Plastic Collapse ◽  
Moment Ratio ◽  
Tension And Compression ◽  
And Storage ◽  
Moment Ratio Diagram

Assessment of the local thin area should be undertaken for both tension and compression bending. In this paper, simplified reference stresses for a flaw in a cylinder are proposed. By using these results, a newly-developed p-M (internal pressure ratio and external bending moment ratio) diagram which can evaluate the plastic collapse condition for pressure equipment such as vessels, piping and storage tanks with a local thin area simultaneously subjected to internal pressure, p, and external bending moment, M, due to earthquake, etc. is proposed. The p-M line is verified by comparison with the FEA results and the numerous results of experiment for a cylinder with a volumetric flaw obtained through the reference literatures. It was clarified that the differences in plastic collapse limit between the p-M line and DNV guideline under both internal pressure and compression moment became evident where the outer diameter/wall thickness of a cylinder is large and the yield ratio of the material is small.

Plastic Collapse Assessment Procedure in P-M Diagram Method for Pipe Bends With a Local Thin Area Under Combined Pressure and Out-of-Plane Bending Moment

2012 ◽  
Author(s):  
Kenji Oyamada ◽  
Shinji Konosu ◽  
Takashi Ohno
Keyword(s):  
Internal Pressure ◽  
Pressure Ratio ◽  
Bending Moment ◽  
Piping System ◽  
Assessment Procedure ◽  
Plastic Collapse ◽  
Diagram Method ◽  
Out Of Plane ◽  
Plane Bending ◽  
Collapse Assessment

Pipe bends are common elements in piping system such as power or process piping, and local thinning are typically occurred on pipe bends due to erosion or corrosion. Therefore, it is important to establish the plastic collapse condition for pipe bends having a local thin area (LTA) under combined internal pressure and external bending moment. In this paper, a simplified plastic collapse assessment procedure in p-M (internal pressure ratio and external bending moment ratio) diagram method for pipe bends with a local thin area simultaneously subjected to internal pressure, p, and external out-of-plane bending moment, M, due to earthquake, etc., is proposed, which is derived from the reference stress. In this paper, only cases of that an LTA is located in the crown of pipe bends are considered. The plastic collapse loads derived from the p-M diagram method are compared with the results of both experiments and FEA for pipe bends of the same size with various configurations of an LTA.

Procedure for Plastic Collapse Assessment of a Local Thin Area Near Vessel and Nozzle Intersections Subjected to Internal Pressure and External Loadings

2015 ◽  
Author(s):  
Shinji Konosu ◽  
Kenta Ogasawara ◽  
Kenji Oyamada
Keyword(s):  
Internal Pressure ◽  
Critical Region ◽  
Pressure Ratio ◽  
Branch Pipe ◽  
Bending Moment ◽  
Plastic Collapse ◽  
Element Analysis ◽  
Diagram Method ◽  
External Moment ◽  
Collapse Assessment

This paper develops a procedure for plastic collapse assessment of vessel (run pipe) - nozzle (branch pipe) intersections with an arbitrarily positioned local thin area (LTA) under different loading conditions, namely internal pressure, external moment on a nozzle applied along various directions with respect to the vessel main axis, and pure bending moment on a vessel. Although simplified procedures for plastic collapse assessment based on the p-M (internal pressure ratio and external bending moment ratio) diagram method have been previously proposed for straight cylindrical vessels and pipe bends with an LTA, very few studies have dealt with the determination of plastic collapse load for an LTA in the critical region of intersecting vessels subjected to internal pressure and external moment loading. This is likely due to the complexity of the stresses caused by the applied loads in the critical region, which arises from geometric discontinuities. In this paper, simple and empirical formulae for predicting conservative plastic collapse loads for an LTA in the critical region of the intersecting vessels are proposed based on the analytical results of stresses at defect-free vessel-nozzle intersections by using linear finite element analysis (FEA). Localized elastic stress retardation factors are taken into account in the evaluation by the results of a non-linear FEA. Consequently, a p-M diagram method is developed for application to vessel-nozzle intersections with an LTA.

Validity of Assessment Procedure in p-M Method for Multiple Volumetric Flaws

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Shinji Konosu ◽  
Masato Kano ◽  
Norihiko Mukaimachi ◽  
Shinichiro Kanamaru
Keyword(s):  
Internal Pressure ◽  
Bending Moment ◽  
Pressure Vessels ◽  
Assessment Procedure ◽  
Plastic Collapse ◽  
Storage Tanks ◽  
Collapse Load ◽  
Element Analysis ◽  
The Status ◽  
Single Flaw

General components such as pressure vessels, piping, storage tanks, and so on are designed in accordance with the construction codes based on the assumption that there are no flaws in such components. There are, however, numerous instances in which in-service single or multiple volumetric flaws such as local thin areas are found in the equipment concerned. Therefore, it is necessary to establish a fitness for service rule, which is capable of evaluating these flaws. The procedure for a single flaw or multiple flaws has recently been proposed for assessing the flaws in the p-M (pressure-moment) diagram, which is an easy way to visualize the status of the component with flaws simultaneously subjected to internal pressure p and external bending moment M due to earthquake, etc. If the assessment point (Mr,pr) lies inside the p-M line, the component with flaws is judged to be safe. In this paper, numerous experiments and finite element analysis for a cylinder with external multiple volumetric flaws were conducted under (1) pure internal pressure, (2) pure external bending moment, and (3) subjected simultaneously to both internal pressure and external bending moment, in order to determine the plastic collapse load at volumetric flaws by applying the twice-elastic slope (TES) as recommended by ASME. It has been clarified that the collapse (TES) loads are much the same as those calculated under the proposed p-M line based on the measured yield stress.

Development of Simplified Plastic Collapse Assessment Procedure for Vessel With Internal Surface Flaw

2007 ◽  
Author(s):  
Shinji Konosu ◽  
Kenji Oyamada
Keyword(s):  
Internal Pressure ◽  
Bending Moment ◽  
Internal Surface ◽  
Outer Radius ◽  
Surface Flaw ◽  
Assessment Procedure ◽  
Plastic Collapse ◽  
Diagram Method ◽  
Surface Flaws ◽  
And Storage

A simplified assessment procedure using the p-M diagram, which can evaluate the plastic collapse load for pressure equipment such as vessels, piping and storage tanks with an internal surface flaw simultaneously subjected to internal pressure, p, and external bending moment, M, due to earthquake, etc., is derived by taking into account the influence of internal pressure acting on the flaw surface. For an internal surface flaw subjected to pressure, the already-proposed p-M diagram for an external flaw can be applied if the parameters for an internal surface flaw proposed in this paper are used. And the plastic collapse loads derived from the p-M diagram method are being verified by comparison with experimental results. It has been clarified that the parameters for internal surface flaws are also the same as those for external surface flaws where the ratio of thickness to outer radius of a vessel is significantly smaller than unity and internal pressure is small.

Development of Simplified Plastic Collapse Assessment Procedure for Elbow With an External Surface Flaw Simultaneously Subjected to Internal Pressure and External Bending Moment

2008 ◽  
Author(s):  
Kenji Oyamada ◽  
Shinji Konosu
Keyword(s):  
Internal Pressure ◽  
External Surface ◽  
Pressure Ratio ◽  
Bending Moment ◽  
Cylindrical Part ◽  
Surface Flaw ◽  
Assessment Procedure ◽  
Plastic Collapse ◽  
Diagram Method ◽  
The Status

A simplified assessment procedure using the p-M (internal pressure ratio and external bending moment ratio) diagram, which can evaluate the plastic collapse load for an elbow with an external surface flaw simultaneously subjected to internal pressure, p, and external bending moment, M, due to earthquake, etc., is derived. The p-M diagram evaluation is an easy way to visualize the status of components with a flaw. For an elbow with an external surface flaw, the already-proposed p-M diagram by one of authors for the cylindrical part of pressure equipment such as vessels, pipes, etc. with a surface flaw can be applied if the parameters proposed in this paper are used. The plastic collapse loads derived from the p-M diagram method are being verified by comparison with existing experimental and FEA results.

scholarly journals Flexural-Torsional Vibration of Thin-Walled Beams Subjected to Combined Initial Axial Load and End Bending Moment: Application to the Design of Saw Tooth Blades

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Van Binh Phung ◽  
Anh Tuan Nguyen ◽  
Hoang Minh Dang ◽  
Thanh-Phong Dao ◽  
V. N. Duc
Keyword(s):  
Boundary Conditions ◽  
Axial Load ◽  
Stability Boundary ◽  
Bending Moment ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Rayleigh Method ◽  
Thin Walled ◽  
The Stability ◽  
Fixed End

The present paper analyzes the vibration issue of thin-walled beams under combined initial axial load and end moment in two cases with different boundary conditions, specifically the simply supported-end and the laterally fixed-end boundary conditions. The analytical expressions for the first natural frequencies of thin-walled beams were derived by two methods that are a method based on the existence of the roots theorem of differential equation systems and the Rayleigh method. In particular, the stability boundary of a beam can be determined directly from its first natural frequency expression. The analytical results are in good agreement with those from the finite element analysis software ANSYS Mechanical APDL. The research results obtained here are useful for those creating tooth blade designs of innovative frame saw machines.

scholarly journals A Review on Numerical Analysis of RC Flat Slabs Exposed to Fire

2020 ◽  
Vol 27 (1) ◽  
pp. 1-5
Author(s):  
Hanadi Naji ◽  
Nibras Khalid ◽  
Mutaz Medhlom
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Numerical Analysis ◽  
Bending Moment ◽  
Mechanical And Thermal Properties ◽  
Vertical Deflection ◽  
Element Analysis ◽  
Flat Slabs ◽  
Numerical Studies ◽  
The Finite Element Analysis

This paper aims at presenting and discussing the numerical studies performed to estimate the mechanical and thermal behavior of RC flat slabs at elevated temperature and fire. The numerical analysis is carried out using finite element programs by developing models to simulate the performance of the buildings subjected to fire. The mechanical and thermal properties of the materials obtained from the experimental work are involved in the modeling that the outcomes will be more realistic. Many parameters related to fire resistance of the flat slabs have been studied and the finite element analysis results reveal that the width and thickness of the slab, the temperature gradient, the fire direction, the exposure duration and the thermal restraint are important factors that influence the vertical deflection, bending moment and force membrane of the flat slabs exposed to fire. However, the validation of the models is verified by comparing their results to the available experimental date. The finite element modeling contributes in saving cost and time consumed by experiments.

Design and Comprehensive Performance Analysis of IS-LEJ Hinges

2018 ◽  
Author(s):  
Yanlin Li ◽  
Lifang Qiu ◽  
Jinglin Wang ◽  
Zhongtian Xie
Keyword(s):  
Theoretical Formula ◽  
Performance Parameters ◽  
Design Requirement ◽  
Bending Properties ◽  
Element Analysis ◽  
Movement Performance ◽  
The Finite Element Analysis ◽  
Comprehensive Performance ◽  
Calculation Results ◽  
Tension And Compression

The lamina emergent torsional (LET) joint is one of the most important components in lamina emergent mechanisms (LEMs), which can play a key role in its movement performance. This paper summarizes the existing hinges and compares their performance. Based on this, eight new flexure hinges are designed and the finite element analysis (FEA) models are created. Their bending properties, tension and compression resistant properties are analyzed respectively. In order to achieve the preliminary judgment of flexible hinge properties, comprehensive performance parameters q1 and q2 are proposed. The comprehensive performance of the eight hinges is compared according to the calculation results of q1 and q2. The theoretical formula of hinge with best performance is deduced and verified. Finally, the effect of length on the comprehensive performance of the eight hinges are analyzed. The result shows that the structure meets the design requirement of lifting comprehensive performance of hinges.

Validity of Assessment Procedure in p-M Method for Multiple Volumetric Flaws

2008 ◽  
Author(s):  
Shinji Konosu ◽  
Masato Kano ◽  
Norihiko Mukaimachi ◽  
Shinichiro Kanamaru
Keyword(s):  
Internal Pressure ◽  
Yield Stress ◽  
Bending Moment ◽  
Pressure Vessels ◽  
Assessment Procedure ◽  
Plastic Collapse ◽  
Storage Tanks ◽  
Collapse Load ◽  
The Status ◽  
Single Flaw

General components such as pressure vessels, piping, storage tanks and so on are designed in accordance with the construction codes based on the assumption that there are no flaws in such components. There are, however, numerous instances in which in-service single or multiple volumetric flaws (local thin areas; volumetric flaws) are found in the equipment concerned. Therefore, it is necessary to establish a Fitness for Service (FFS) rule, which is capable of judging these flaws. The procedure for a single flaw or multiple flaws has recently been proposed by Konosu for assessing the flaws in the p–M (pressure-moment) Diagram, which is an easy way to visualize the status of the component with flaws simultaneously subjected to internal pressure, p and external bending moment, M due to earthquake, etc. If the assessment point (Mr, pr) lies inside the p–M line, the component with flaws is judged to be safe. In this paper, numerous experiments and FEAs for a cylinder with external multiple volumetric flaws were conducted under (1) pure internal pressure, (2) pure external bending moment, and (3) subjected simultaneously to both internal pressure and external bending moment, in order to determine the plastic collapse load at volumetric flaws by applying the twice-elastic slope (TES) as recommended by ASME. It has been clarified that the collapse (TES) loads are much the same as those calculated under the proposed p–M line based on the measured yield stress.

Sign in / Sign up

Export Citation Format

Share Document