Experimental and Finite-Element Studies of Buried Pipes Connected by a Bellow Joint under Cyclic Shear Loading

2021 ◽  
Vol 12 (4) ◽  
pp. 04021057
Author(s):  
Yang Lv ◽  
Chun-Feng Liu ◽  
Xin Huang ◽  
Yu Chen ◽  
Nawawi Chouw
1996 ◽  
Vol 31 (1) ◽  
pp. 9-24 ◽  
Author(s):  
S J Hardy ◽  
M K Pipelzadeh

This paper describes the results of a study of the elastic–plastic behaviour of short flat bars with projections subjected to monotonic and cyclic shear loading using finite element analysis. Six geometries, associated with both local and remote restraints (resulting in elastic stress concentration factors in the range 1.90–7.20), are considered. Three simple bilinear elastic–plastic material models are assumed. The results have been normalized with respect to material properties so that they can be applied to geometrically similar components made from other materials which can be represented by the same materials models.


PCI Journal ◽  
1996 ◽  
Vol 41 (3) ◽  
pp. 64-80 ◽  
Author(s):  
Khaled A. Soudki ◽  
Jeffrey S. West ◽  
Sami H. Rizkalla ◽  
Bruce Blackett

Author(s):  
Ming Zhang ◽  
Yanyao Jiang ◽  
Chu-Hwa Lee

A three-dimensional finite element (FE) model with the consideration of the helix angle of the threads was developed to simulate the second stage self-loosening of a bolted joint. The second stage self-loosening refers to the graduate reduction in clamping force due to the back-off of the nut. The simulations were conducted for two plates jointed by a bolt and a nut and the joint was subjected to transverse or shear loading. An M12×1.75 bolt was used. The application of the preload was simulated by using an orthogonal temperature expansion method. FE simulations were conducted for several loading conditions with different preloads and relative displacements between the two clamped plates. It was found that due to the application of the cyclic transverse load, micro-slip occurred between the contacting surfaces of the engaged threads of the bolt and the nut. In addition, a cyclic bending moment was introduced on the bolted joint. The cyclic bending moment resulted in an oscillation of the contact pressure on the contacting surfaces of the engaged threads. The micro-slip between the engaged threads and the variation of the contact pressure were identified to be the major mechanisms responsible for the self-loosening of a bolted joint. Simplified finite element models were developed that confirmed the mechanisms discovered. The major self-loosening behavior of a bolted joint can be properly reproduced with the FE model developed. The results obtained agree quantitatively with the experimental observations.


2019 ◽  
Vol 8 (3) ◽  
pp. 87-98
Author(s):  
Alaa Abbas ◽  
Felicite Ruddock ◽  
Rafid Alkhaddar ◽  
Glynn Rothwell ◽  
Iacopo Carnacina ◽  
...  

The use of a finite element (FE) method and selection of the appropriate model to simulate soil elastoplastic behaviour has confirmed the importance and sensitivity of the soil properties on the accuracy when compared with experimental data. The properties of the filling soil play a significant role in determining levels of deformation and displacement of both the soil and subterranean structures when using the FE model simulation. This paper investigates the impact of the traffic load on the filling soil deformation when using the traditional method, one pipe in a trench, and a new method, two pipes in a single trench one over the other, for setting up a separate sewer system. The interaction between the buried pipes and the filling soils has been simulated using an elastoplastic FE model. A modified Drucker–Prager cap constitutive model was used to simulate the stress-strain behaviours of the soil. A series of laboratory tests were conducted to identify the elastoplastic properties of the composite soil used to bury the pipes. The FE models were calibrated using a physical lab model for testing the buried pipes under applied load. This allows the FE model to be confidently upgraded to a full-scale model. The pipe-soil interactions were found to be significantly influenced by the soil properties, the method of placing the pipes in the trench and the diameters of the buried pipes. The deformation of the surface soil was decreased by approximately 10% when using the new method of setting up the separate sewer.


2013 ◽  
Vol 12 (4) ◽  
pp. 1615-1638 ◽  
Author(s):  
Georgia D. Kremmyda ◽  
Yasin M. Fahjan ◽  
Spyros G. Tsoukantas

2018 ◽  
Vol 199 ◽  
pp. 09008
Author(s):  
Philipp Mahrenholtz ◽  
Jae-Yeol Cho ◽  
Ja-Min Park ◽  
Rolf Eligehausen

A critical performance aspect of FRP retrofitted concrete elements is the bonding of the FRP sheet to the concrete surface. In general, the performance is limited by the debonding of the loaded FRP sheets from the concrete surface. One method to delay debonding and enhance the capacity is the use of FRP anchors which interlock the FRP sheet to the concrete body. FRP anchors are made of rolled FRP fibres epoxied into in predrilled boreholes. There are a considerable number of studies on FRP strengthening methods available, and also FRP anchors attract more attention of the research community recently. However, to date FRP anchors were tested in a system together with the FRP sheet attached to the concrete, inhibiting the development of general design models. Moreover, the anchor behaviour was never tested for cyclic loads, though most applications are for seismic retrofitting schemes and cyclic shear loading generally results in reduced load capacity due to fatigue failure. To overcome the deficit in knowledge, shear tests on various FRP anchors were carried out. For these tests, FRP anchors were installed in concrete specimens on a separating steel section. The FRP anchor was then directly loaded to determine the capacity of the isolated component. This paper describes the testing approach and procedure. Details on the experimental results for static tests are presented and an outlook on seismic tests is given.


2020 ◽  
Vol 10 (8) ◽  
pp. 2834
Author(s):  
Mohsen Saleh Asheghabadi ◽  
Xiaohui Cheng

In this study, a soil–tunnel model for clay under earthquake loading is analyzed, using finite element methods and a kinematic hardening model with the Von Mises failure criterion. The results are compared with those from the linear elastic–perfectly plastic Mohr–Coulomb model. The latter model does not consider the stiffness degradation caused by imposing cyclic loading and unloading to the soil, whereas the kinematic hardening model can simulate this stiffness degradation. The parameters of the kinematic hardening model are calibrated based on the results of experimental cyclic tests and finite element simulation. Here, two methods—one using data from cyclic shear tests, and the other a new method using undrained cyclic triaxial tests—are used to calibrate the parameters. The parameters investigated are the peak ground acceleration (PGA), tunnel lining thickness, tunnel shape, and tunnel embedment depth, all of which have an effect on the resistance of the shallow tunnel to the stresses and deformations caused by the surrounding clay soils. The results show that unlike traditional models, the nonlinear kinematic hardening model can predict the response reasonably well, and it is able to create the hysteresis loops and consider the soil stiffness degradation under the seismic loads.


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