scholarly journals Analytical Evaluation of Reinforced Concrete Pier and Cast-in-Steel-Shell Pile Connection Behavior considering Steel-Concrete Interface

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Jiho Moon ◽  
Dawn E. Lehman ◽  
Charles W. Roeder ◽  
Hak-Eun Lee ◽  
Tae-Hyung Lee
Keyword(s):  
Reinforced Concrete ◽  
Large Diameter ◽  
Structural Behavior ◽  
Steel Shell ◽  
Fe Model ◽  
Fe Method ◽  
Design Guideline ◽  
Composite Action ◽  
Embedment Length ◽  
The Cost

The seismic design of bridges may require a large-diameter deep pile foundation such as a cast-in-steel-shell (CISS) pile where a reinforced concrete (RC) member is cast in a steel casing. In practice, the steel casing is not considered in the structural design and the pile is assumed to be an RC member. It is partially attributed to the difficulties in evaluation of composite action of a CISS pile. However, by considering benefits provided by composite action of the infilled concrete and the steel casing, both the cost and size of CISS pile can be reduced. In this study, the structural behavior of the RC pier and the CISS pile connection is simulated by using an advanced 3D finite element (FE) method, where the interface between the steel and concrete is also modeled. Firstly, the FE model is verified. Then, the parametric study is conducted. The analysis results suggest that the embedment length and the friction coefficient between the steel casing and the infilled concrete affect the structural behavior of the RC pier. Finally, the minimum embedment length with reference to the AASHTO design guideline is suggested considering the composite action of the CISS pile.

Structural Behavior of Precast Reinforced Concrete Shear Walls with Large Diameter Bars

2019 ◽  
Vol 116 (5) ◽  
Author(s):  
Xin Chen ◽  
Ming Liu ◽  
Fabio Biondini ◽  
Gianpaolo Rosati
Keyword(s):  
Reinforced Concrete ◽  
Large Diameter ◽  
Shear Walls ◽  
Structural Behavior

scholarly journals Analysis of nodal stress on reinforced concrete two-pile caps supported on steel piles

2020 ◽  
Vol 13 (6) ◽  
Author(s):  
Rodrigo Gustavo Delalibera ◽  
Marco Aurélio Tomaz ◽  
Vitor Freitas Gonçalves ◽  
José Samuel Giongo
Keyword(s):  
Reinforced Concrete ◽  
Structural Behavior ◽  
Concrete Piles ◽  
Strut And Tie ◽  
Concrete Pile ◽  
Steel Piles ◽  
Pile Cap ◽  
Pile Caps ◽  
Embedment Length ◽  
Strut And Tie Model

abstract: Reinforced concrete pile caps may be designed trough plastic models (strut and tie model) or models based on bending theory. The formulae available for verifying the stress is based on caps supported on concrete piles, with few studies about the stress distribution on caps supported on steel piles. To analyze the structural behavior of caps supported on steel piles, as well as the stress on the superior and inferior nodal zones, four two-pile caps supported on steel piles were tested. The variables were the embedment length and in one of the specimens a steel plate was welded on top of both piles. It was observed that the embedment length has substantial influence on pile cap structural behavior. It was concluded that, to verify the stress on inferior nodal zone of the cap, aside from pile area, an area of concrete confined between the flaps of the pile must be considered.

A novel model of Z-pin insertion in prepreg based on fracture mechanics

2021 ◽  
pp. 095440542110144
Author(s):  
Guobiao Ji ◽  
Liang Cheng ◽  
Shaohua Fei ◽  
Jiangxiong Li ◽  
Yinglin Ke
Keyword(s):  
Fracture Toughness ◽  
Fracture Mechanics ◽  
Analytical Model ◽  
Model Parameters ◽  
Force Model ◽  
Fe Model ◽  
Cohesive Elements ◽  
Fe Method ◽  
Insertion Force ◽  
Mechanics Model

Through-thickness reinforcement is a promising solution to the problem of delamination susceptibility in laminated composites. Modeling Z-pin–prepreg interaction is essential for accurate robotics-assisted Z-pin insertion. In this paper, a novel Z-pin insertion force model combining the classical cohesive finite element (FE) method with a dynamic analytical fracture mechanics model is proposed. The velocity-dependent cohesive elements, in which the fracture toughness is provided by the analytical model, are implemented in Z-pin insertion FE model to predict the crack initiation and propagation. Then Z-pin insertion experiments are performed on prepreg sample with metallic Z-pins at different velocities to identify the analytical model parameters and validate the simulation predictions offered by the model. Dynamics of Z-pin interaction with inhomogeneous prepreg is described and the effects of insertion velocity on prepreg contact force are studied. Results show that the force model agrees well with experiments and the fracture toughness rises with the increasing Z-pin insertion velocity.

Development and analysis of composite overwrapped pressure vessels for hydrogen storage

2021 ◽  
pp. 002199832110335
Author(s):  
Osman Kartav ◽  
Serkan Kangal ◽  
Kutay Yücetürk ◽  
Metin Tanoğlu ◽  
Engin Aktaş ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Damage Model ◽  
Pressure Vessels ◽  
Filament Winding ◽  
Burst Pressure ◽  
Fe Model ◽  
Fe Method ◽  
Liner Material ◽  
Mechanical Performances ◽  
Metallic Liner

In this study, composite overwrapped pressure vessels (COPVs) for high-pressure hydrogen storage were designed, modeled by finite element (FE) method, manufactured by filament winding technique and tested for burst pressure. Aluminum 6061-T6 was selected as a metallic liner material. Epoxy impregnated carbon filaments were overwrapped over the liner with a winding angle of ±14° to obtain fully overwrapped composite reinforced vessels with non-identical front and back dome layers. The COPVs were loaded with increasing internal pressure up to the burst pressure level. During loading, deformation of the vessels was measured locally with strain gauges. The mechanical performances of COPVs designed with various number of helical, hoop and doily layers were investigated by both experimental and numerical methods. In numerical method, FE analysis containing a simple progressive damage model available in ANSYS software package for the composite section was performed. The results revealed that the FE model provides a good correlation as compared to experimental strain results for the developed COPVs. The burst pressure test results showed that integration of doily layers to the filament winding process resulted with an improvement of the COPVs performance.

scholarly journals Modelling human skull growth: a validated computational model

2017 ◽  
Vol 14 (130) ◽  
pp. 20170202 ◽  
Author(s):  
Joseph Libby ◽  
Arsalan Marghoub ◽  
David Johnson ◽  
Roman H. Khonsari ◽  
Michael J. Fagan ◽  
...  
Keyword(s):  
Computational Model ◽  
Three Dimensional ◽  
Basic Knowledge ◽  
Fe Model ◽  
Adult Size ◽  
Fe Method ◽  
Percentage Difference ◽  
Skull Growth

During the first year of life, the brain grows rapidly and the neurocranium increases to about 65% of its adult size. Our understanding of the relationship between the biomechanical forces, especially from the growing brain, the craniofacial soft tissue structures and the individual bone plates of the skull vault is still limited. This basic knowledge could help in the future planning of craniofacial surgical operations. The aim of this study was to develop a validated computational model of skull growth, based on the finite-element (FE) method, to help understand the biomechanics of skull growth. To do this, a two-step validation study was carried out. First, an in vitro physical three-dimensional printed model and an in silico FE model were created from the same micro-CT scan of an infant skull and loaded with forces from the growing brain from zero to two months of age. The results from the in vitro model validated the FE model before it was further developed to expand from 0 to 12 months of age. This second FE model was compared directly with in vivo clinical CT scans of infants without craniofacial conditions ( n = 56). The various models were compared in terms of predicted skull width, length and circumference, while the overall shape was quantified using three-dimensional distance plots. Statistical analysis yielded no significant differences between the male skull models. All size measurements from the FE model versus the in vitro physical model were within 5%, with one exception showing a 7.6% difference. The FE model and in vivo data also correlated well, with the largest percentage difference in size being 8.3%. Overall, the FE model results matched well with both the in vitro and in vivo data. With further development and model refinement, this modelling method could be used to assist in preoperative planning of craniofacial surgery procedures and could help to reduce reoperation rates.

scholarly journals Influence of Pile Diameter and Aspect Ratio on the Lateral Response of Monopiles in Sand with Different Relative Densties

2021 ◽  
Vol 9 (6) ◽  
pp. 618
Author(s):  
Huan Wang ◽  
Lizhong Wang ◽  
Yi Hong ◽  
Amin Askarinejad ◽  
Ben He ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Large Diameter ◽  
Pressure Coefficient ◽  
Offshore Wind ◽  
Fe Model ◽  
Soil Pressure ◽  
Pile Diameter ◽  
Centrifuge Tests ◽  
Aspect Ratios ◽  
Wide Range

The large-diameter monopiles are the most preferred foundation used in offshore wind farms. However, the influence of pile diameter and aspect ratio on the lateral bearing behavior of monopiles in sand with different relative densities has not been systematically studied. This study presents a series of well-calibrated finite-element (FE) analyses using an advanced state dependent constitutive model. The FE model was first validated against the centrifuge tests on the large-diameter monopiles. Parametric studies were performed on rigid piles with different diameters (D = 4–10 m) and aspect ratios (L/D = 3–7.5) under a wide range of loading heights (e = 5–100 m) in sands with different relative densities (Dr = 40%, 65%, 80%). The API and PISA p-y models were systematically compared and evaluated against the FE simulation results. The numerical results revealed a rigid rotation failure mechanism of the rigid pile, which is independent of pile diameter and aspect ratio. The computed soil pressure coefficient (K = p/Dσ′v) of different diameter piles at same rotation is a function of z/L (z is depth) rather than z/D. The force–moment diagrams at different deflections were quantified in sands of different relative density. Based on the observed pile–soil interaction mechanism, a simple design model was proposed to calculate the combined capacity of rigid piles.

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