Burst pressure of corroded pipelines considering combined axial forces and bending moments

2019 ◽  
Vol 186 ◽  
pp. 43-51 ◽  
Author(s):  
Bipul Chandra Mondal ◽  
Ashutosh Sutra Dhar
Keyword(s):  
Burst Pressure ◽  
Bending Moments ◽  
Axial Forces

scholarly journals 3-D Numerical Study of Mechanical Behaviors of Pile-Anchor System

2014 ◽  
Vol 580-583 ◽  
pp. 238-242
Author(s):  
Ri Cheng Liu ◽  
Bang Shu Xu ◽  
Bo Li ◽  
Yu Jing Jiang
Keyword(s):  
Simulation Analysis ◽  
Numerical Study ◽  
Bending Moments ◽  
Mechanical Behaviors ◽  
Foundation Pit ◽  
Anchor System ◽  
Anchor Cable ◽  
Axial Forces ◽  
Toppling Failure ◽  
Potential Failure

Mechanical behaviors of pile-soil effect and anchor-soil effect are significantly important in supporting engineering activities of foundation pit. In this paper, finite difference method (FDM) was utilized to perform the numerical simulation of pile-anchor system, composed of supporting piles and pre-stressed anchor cables. Numerical simulations were on the basis of the foundation pit of Jinan’s West Railway Station, and 3D simulation analysis of foundation pit has been prepared during the whole processes of excavation, supporting and construction. The paper also analyzed the changes of bending moments of piles and axial forces of cables, and discussed mechanical behaviors of pile-anchor system, through comparisons with field monitoring. The results show that the parameters concluding vertical gridding’s number, cohesion of pile and soil, and pile stiffness have robust influences on supporting elements’ behaviors. Mechanical behaviors of supporting pile and axial forces of anchor cable changed dramatically, indicating that the potential failure form was converted from toppling failure to sliding failure.

Stiffened Hangers: an Often Overlooked Tool for Conceptual Design of Tied-Arch Footbridges

2021 ◽  
Author(s):  
Juan José Jorquera-Lucerga ◽  
Juan Manuel GARCÍA-GUERRERO
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Structural Response ◽  
Bending Moments ◽  
Structural Element ◽  
Axial Forces ◽  
Limited Effectiveness ◽  
Out Of Plane ◽  
Arch Bridges ◽  
Fixed End

<p>In tied-arch bridges, the way the arch and the deck are connected may become crucial. The deck is usually suspended from hangers made out of steel pinned cables capable of resisting axial forces only. However, a proper structural response, (both in-plane and out-of-plane) may be ensured by fixing and stiffening the hangers in order to resist, additionally, shear forces and bending moments. This paper studies the effect of different pinned and stiffened hanger arrangements on the structural behavior of the tied-arch footbridges, with the intention of providing designers with useful tools at the early steps of design. As a major conclusion, regarding the in-plane behavior, hangers composed of cables (either with vertical, Nielsen-Löhse or network arrangements) are recommended due to its low cost and ease of erection. Alternatively, longitudinally stiffened hangers, fixed at both ends, can be used. Regarding the out-of-plane behavior, and in addition to three-dimensional arrangements of cables, of limited effectiveness, transversally stiffened hangers fixed at both ends are the most efficient arrangement. A configuration almost as efficient can be achieved by locating a hinge at the end corresponding to the most flexible structural element (normally the arch). Its efficiency is further improved if the cross-section tapers from the fixed end to the pinned end.</p>

Analytical Computational Models for Relationship between Ultimate Bending Moment of Concrete Segments and Axial Force

2020 ◽  
Vol 853 ◽  
pp. 177-181
Author(s):  
Zhi Yun Wang ◽  
Shou Ju Li
Keyword(s):  
Numerical Simulation ◽  
Computational Model ◽  
Axial Force ◽  
Computational Models ◽  
Plane Deformation ◽  
Bending Moment ◽  
Analytical Models ◽  
Bending Moments ◽  
Axial Forces ◽  
Practical Engineering

Concrete segments are widely used to support soil and water loadings in shield-excavated tunnels. Concrete segments burden simultaneously to the loadings of bending moments and axial forces. Based on plane deformation assumption of material mechanics, in which plane section before bending remains plane after bending, ultimate bending moment model is proposed to compute ultimate bearing capacity of concrete segments. Ultimate bending moments of concrete segments computed by analytical models agree well with numerical simulation results by FEM. The accuracy of proposed analytical computational model for ultimate bending moment of concrete segments is numerically verified. The analytical computational model and numerical simulation for a practical engineering case indicate that the ultimate bending moment of concrete segments increases with increase of axial force on concrete segment in the case of large eccentricity compressive state.

scholarly journals Mechanical signals at the base of a rat vibrissa: the effect of intrinsic vibrissa curvature and implications for tactile exploration

2012 ◽  
Vol 107 (9) ◽  
pp. 2298-2312 ◽  
Author(s):  
Brian W. Quist ◽  
Mitra J. Z. Hartmann
Keyword(s):  
Concave Side ◽  
Bending Moments ◽  
Intrinsic Curvature ◽  
Natural Behavior ◽  
Axial Forces ◽  
Detailed Surface ◽  
Increased Sensitivity ◽  
Mystacial Vibrissae ◽  
Almost All

Rats actively tap and sweep their large mystacial vibrissae (whiskers) against objects to tactually explore their surroundings. When a vibrissa makes contact with an object, it bends, and this bending generates forces and bending moments at the vibrissa base. Researchers have only recently begun to quantify these mechanical variables. The present study quantifies the forces and bending moments at the vibrissa base with a quasi-static model of vibrissa deflection. The model was validated with experiments on real vibrissae. Initial simulations demonstrated that almost all vibrissa-object collisions during natural behavior will occur with the concave side of the vibrissa facing the object, and we therefore paid particular attention to the role of the vibrissa's intrinsic curvature in shaping the forces at the base. Both simulations and experiments showed that vibrissae with larger intrinsic curvatures will generate larger axial forces. Simulations also demonstrated that the range of forces and moments at the vibrissal base vary over approximately three orders of magnitude, depending on the location along the vibrissa at which object contact is made. Both simulations and experiments demonstrated that collisions in which the concave side of the vibrissa faces the object generate longer-duration contacts and larger net forces than collisions with the convex side. These results suggest that the orientation of the vibrissa's intrinsic curvature on the mystacial pad may increase forces during object contact and provide increased sensitivity to detailed surface features.

Effect of pile driving on adjacent piles in clay

1994 ◽  
Vol 31 (6) ◽  
pp. 856-867 ◽  
Author(s):  
H.G. Poulos
Keyword(s):  
Structural Damage ◽  
Tensile Failure ◽  
Pile Driving ◽  
Bending Moments ◽  
Depth Of Penetration ◽  
Vertical Movements ◽  
Concrete Piles ◽  
Axial Forces ◽  
Model Pile ◽  
Soil Movements

When a pile is driven into clay, horizontal and vertical movements are developed in the soil surrounding the pile. These movements will tend to develop axial forces and bending moments in adjacent piles that have already been installed. Possible consequences for these piles are (i) structural damage or cracking (of concrete piles) arising from the induced bending moments, (ii) tensile failure of the piles due to the induced axial forces, and (iii) lifting-off of the pile tip from the bearing stratum due to the axial induced movements. This paper describes the results of a theoretical analysis of the bending moments and axial forces developed in a pile due to driving of an adjacent pile in clay. The analysis uses approximate distributions of horizontal and vertical soil movements caused by pile driving, developed from a "strain-path" analysis, together with inferences from model pile test data. An examination is made of various factors that may influence the induced bending moments and forces, including pile spacing, depth of penetration of the adjacent pile, and number of piles driven. For a number of published case histories comparisons are made between theoretical and measured axial and lateral pile movements. In general, satisfactory agreement is found. Key words : foundations, lateral movements, pile driving, settlement, soil displacement.

scholarly journals Perencanaan Perencanaan Sruktur Jembatan Lengkung Pada Sungai Sombe-Lewara

2020 ◽  
Vol 4 (2) ◽  
pp. 14-25
Author(s):  
Atur P. N. Siregar ◽  
Anwar Dolu ◽  
M Z H Ragalutu
Keyword(s):  
Structural Analysis ◽  
Bending Moment ◽  
Bending Moments ◽  
Long Span Bridges ◽  
Community Needs ◽  
Final Project ◽  
Long Span ◽  
Axial Forces ◽  
Bridge Type ◽  
Reinforcement Design

Kecamatan Kinovaro secara geografis memiliki banyak sungai yang panjang dan lebar yang menjadi kendala dalam proses pemenuhan kebutuhan masyarakat dan perkembangan daerah tersebut. Maka perlu adanya fasilitas penunjang, salah satunya adalah jembatan. Jembatan merupakan konstruksi vital maka  harus didesain sedemikian rupa agar mampu menerima beban dengan baik. Jembatan tipe portal lengkung dapat menjadi alternatif untuk jembatan bentang panjang, karena selain bentuknya yang memiliki nilai estetika, jembatan dengan tipe pelengkung juga dapat mereduksi momen lentur sehingga penampang yang diperoleh menjadi lebih efisien. Abstract Kinovaro is a subdistrict where has many long and wide rivers and being obstacles in the process of fulfilling community needs and the development of the area. So that it needs to have a facilitis, one of that is a bridge. Bridges is important constructions so it needs to be designed carepully in order to have a proper calculation. Curved bridge type can be an alternative for long span bridges, because it has a nice aesthetic value, can also reduce bending moments so that it can provide an optimum cross section. The purpose of this Final Project is to obtain bending moments and curved axial forces, dimensions and reinforcement. The method used for structural analysis is the finite element method through the SAP2000 program, while for reinforcement design using the strength method based on SNI 2847-2013. The results of structural analysis, the are critical bending moment is 21869.332 kN.m and the critical axial force is 15944.307 kN, both of which are in the arching position. From the design results is found out that the girder dimensions of 60 x 80 cm. Thickness of the top arch is 60 cm and nearby support is 140 cm. While the column thickness at the top of the arch is 40 cm and nearby support is 80 cm. From the results of reinforcement design, the girder reinforcement of 16D25 mm was obtained on the support, and of 10D25 mm was at the middle length of the beam. Reinforcement of columns was obtained of D25-100 mm nearby support area and D25-200 mm at the top area. Whereas for the arches obtained of D25-80 mm for the supporting area and D25-100 mm at the top of the arch area. Tujuan dari penulisan Tugas Akhir ini adalah untuk mendapatkan momen lentur dan gaya aksial pelengkung, dimensi dan tulangan struktur yang efisien. Metode yang digunakan untuk analisa struktur adalah metode elemen hingga menggunakan program SAP2000, sedangkan untuk perencanaan tulangan menggunakan metode kekuatan berdasarkan SNI 2847-2013. Dari hasil analisa struktur diperoleh momen lentur pelengkung terbesar adalah 21869,332 kN.m dan gaya aksial terbesar adalah 15944,307 kN, keduanya berada pada perletakan pelengkung. Dari hasil perencanaan diperoleh dimensi gelagar 60 x 80 cm, tebal pada puncak pelengkung adalah 60 cm dan pada perletakan adalah 140 cm, sedangkan untuk tebal kolom pada puncak pelengkung adalah 40 cm dan pada perletakan adalah 80 cm. Dari hasil perencanaan tulangan diperoleh tulangan gelagar pada tumpuan 17D25 mm dan lapangan 10D25 mm. Tulangan kolom diperoleh tulangan D25-100 mm untuk daerah perletakan pelengkung dan D25-200 mm pada daerah puncak. Sedangkan untuk pelengkung diperoleh D25-80 mm untuk daerah perletakan dan D25-100 mm pada daerah puncak pelengkung.

Experimental Investigation on Mechanical Properties of Plastic Pipes Reinforced by Cross Helically Steel Wires

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Jinyang Zheng ◽  
Yubin Lu ◽  
Li Xiang ◽  
Xiufeng Lin ◽  
Yancong Zhu ◽  
...  
Keyword(s):  
Failure Modes ◽  
Steel Wire ◽  
Expansion Ratio ◽  
Radial Force ◽  
Burst Pressure ◽  
Pipe Failure ◽  
Axial Forces ◽  
New Type ◽  
Short Time ◽  
Critical Buckling Pressure

A Polyethylene (PE) pipe reinforced by a cross-winding steel wire (PSP) is a new type of plastic-matrix steel composite pipe, which has excellent performance. Its short-time burst pressure, strain, critical buckling pressure, and failure mode under various temperatures were investigated. Experimental results show that PSP has an increase of short-time burst pressure at room temperature up to 129%, ring stiffness up to 19%, and critical buckling pressure up to 57% in comparison with a comparable PE pipe. Failure modes of PSP subjected to internal pressure under various temperatures are found to be ductile burst and excessive deformation, and their transition temperature is about 45°C. Moreover, at the same pressure, the radial expansion ratio of PSP only bearing radial force is much larger than that of PSP bearing both radial and axial forces.

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