scholarly journals A Comparative Study of Piers with DSCT and Steel Piles

2021 ◽  
Vol 21 (6) ◽  
pp. 377-383
Author(s):  
Hyemin Hong ◽  
Sungwon Kim ◽  
Taek Hee Han

Because of climate changes, the demand for securing marine space is increasing owing to problems such as sea level rise, design wave height increase, and lack of land and space, and research on the development of a new high-performance pier has been conducted. In the existing pier supported by steel piles, buckling failure and corrosion problems may lead to a risk of structural safety, and maintenance is difficult owing to a narrow span. The new type of double-skinned composite tubular (DSCT) structure, which has been extensively studied recently, is filled with concrete between the inner and outer tubes, increasing the strength of concrete because of the three-axis confined effect. In addition, it is advantageous in terms of ductility. Furthermore, owing to the hollow cross-section, it is economical because it weighs less than the concrete-filled steel tubular (CFT) structure, effectively saving materials. In this study, the performance of a pier with 30 steel piles and that of a pier supported with 20 DSCT piles was compared under the same external force through finite element analysis. Consequently, it was confirmed that the pier with DSCT piles showed higher performance in displacement and stress than the existing pier with steel piles.

Author(s):  
Huilong Ren ◽  
Yifu Liu ◽  
Chenfeng Li ◽  
Xin Zhang ◽  
Zhaonian Wu

There is an increasing interest in the lightweight design of ship and offshore structures, more specifically, choosing aluminum alloys or other lightweight high-performance materials to build structure components and ship equipments. Due to its better mechanical properties and easy assembly nature, extruded aluminum alloy stiffened plates are widely used in hull structures. When the load on the hull reaches a certain level during sailing, partial or overall instability of stiffened plate makes significant contribution in an event of collapse of the hull structure. It is very necessary to investigate the ultimate strength of aluminum alloy stiffened plate to ensure the ultimate bearing capacity of large aluminum alloy hull structure. Most of studies of the ultimate strength of stiffened plates deal with stiffened plates with T–shaped stiffeners. Stiffeners of other shapes have seldom been explored. In this research, the ultimate strength of six different cross–section aluminum alloy stiffened plates and one steel stiffened plate was studied based on the non–linear finite element analysis (FEA). Taking into account stiffness, weight and other issues, the new cross–section aluminum stiffener has finally been concluded for replacing the original steel stiffener in upper deck of a warship.


2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Yanfu Li

To solve the problem that large torque drilling rig requires high performance of the chuck, this paper introduces the composition and working principle of a normally open hydraulic chuck, as well as the design and calculation method of its bearing capacity and clamping force. Through the use of creo2.0/simulate finite element analysis module, finite element analysis is made on the main structure parts of the chuck. The results show that the parameter selection and structure design of the chuck mechanism meet the requirements of use, which provides a guarantee for improving the reliability of the chuck mechanism and the overall performance of the drilling rig.


2013 ◽  
Vol 457-458 ◽  
pp. 1512-1516
Author(s):  
Si Nan Liu ◽  
Bin Zhang ◽  
Ren Guo Gu

The cable support system in large cross-section cable tunnel, which can solve the cable laying problem of big cross section cable and multi-loop cable effectively, gradually become the development trend of urban electricity transmission. Combined with the structure feature of large cross section shield tunnel, a new type of self-balanced shield tunnel cable support system is proposed. The safety and rationality of this system has been validated by the structure calculation, the finite element analysis of ADINA and the full scale model test. The analysis shows that the system has some advantages, such as excellent whole mechanical characteristics, strong adaptability, convenient construction and low cost. The system can fully satisfy all requirements of the cable tunnel construction and all functions of operation. The stress distribution of the structure is relatively homogeneous, the bearing capacity of components and the global stability of it also meet the requirements. With the test load which is about 1.5 ~ 4.0 times as large as design load, the support system displacement is 0.65 ~ 2.5 mm, which shows that the structure is safe and reliable. The research achievements can provide theoretical basis and experimental basis for the design of large cross-section cable tunnel.


2011 ◽  
Vol 39 (3) ◽  
pp. 193-209 ◽  
Author(s):  
H. Surendranath ◽  
M. Dunbar

Abstract Over the last few decades, finite element analysis has become an integral part of the overall tire design process. Engineers need to perform a number of different simulations to evaluate new designs and study the effect of proposed design changes. However, tires pose formidable simulation challenges due to the presence of highly nonlinear rubber compounds, embedded reinforcements, complex tread geometries, rolling contact, and large deformations. Accurate simulation requires careful consideration of these factors, resulting in the extensive turnaround time, often times prolonging the design cycle. Therefore, it is extremely critical to explore means to reduce the turnaround time while producing reliable results. Compute clusters have recently become a cost effective means to perform high performance computing (HPC). Distributed memory parallel solvers designed to take advantage of compute clusters have become increasingly popular. In this paper, we examine the use of HPC for various tire simulations and demonstrate how it can significantly reduce simulation turnaround time. Abaqus/Standard is used for routine tire simulations like footprint and steady state rolling. Abaqus/Explicit is used for transient rolling and hydroplaning simulations. The run times and scaling data corresponding to models of various sizes and complexity are presented.


2003 ◽  
Vol 31 (3) ◽  
pp. 189-202 ◽  
Author(s):  
D. Zheng

Abstract A procedure based on steady state rolling contact Finite Element Analysis (FEM) has been developed to predict tire cross section tread wear profile under specified vehicle driving conditions. This procedure not only considers the tire construction effects, it also includes the effects of materials, vehicle setup, test course, and driver's driving style. In this algorithm, the vehicle driving conditions are represented by the vehicle acceleration histogram. Vehicle dynamic simulations are done to transform the acceleration histogram into tire loading condition distributions for each tire position. Tire weight loss rates for different vehicle accelerations are generated based on a steady state rolling contact simulation algorithm. Combining the weight loss rate and the vehicle acceleration histogram, nine typical tire loading conditions are chosen with different weight factors to represent tire usage conditions. It is discovered that the tire tread wear rate profile is changing continuously as the tire is worn. Simulation of a new tire alone cannot be used to predict the tire cross-section tread wear profile. For this reason, an incremental tread wear simulation procedure is performed to predict the tire cross section tread wear profile. Compared with actual tire cross-section tread wear profiles, good results are obtained from the simulations.


2021 ◽  
Vol 2 (1) ◽  
pp. 46-62
Author(s):  
Santiago Iglesias-Baniela ◽  
Juan Vinagre-Ríos ◽  
José M. Pérez-Canosa

It is a well-known fact that the 1989 Exxon Valdez disaster caused the escort towing of laden tankers in many coastal areas of the world to become compulsory. In order to implement a new type of escort towing, specially designed to be employed in very adverse weather conditions, considerable changes in the hull form of escort tugs had to be made to improve their stability and performance. Since traditional winch and ropes technologies were only effective in calm waters, tugs had to be fitted with new devices. These improvements allowed the remodeled tugs to counterbalance the strong forces generated by the maneuvers in open waters. The aim of this paper is to perform a comprehensive literature review of the new high-performance automatic dynamic winches. Furthermore, a thorough analysis of the best available technologies regarding towline, essential to properly exploit the new winches, will be carried out. Through this review, the way in which the escort towing industry has faced this technological challenge is shown.


Author(s):  
Manish Kumar ◽  
Pronab Roy ◽  
Kallol Khan

From the recent literature, it is revealed that pipe bend geometry deviates from the circular cross-section due to pipe bending process for any bend angle, and this deviation in the cross-section is defined as the initial geometric imperfection. This paper focuses on the determination of collapse moment of different angled pipe bends incorporated with initial geometric imperfection subjected to in-plane closing and opening bending moments. The three-dimensional finite element analysis is accounted for geometric as well as material nonlinearities. Python scripting is implemented for modeling the pipe bends with initial geometry imperfection. The twice-elastic-slope method is adopted to determine the collapse moments. From the results, it is observed that initial imperfection has significant impact on the collapse moment of pipe bends. It can be concluded that the effect of initial imperfection decreases with the decrease in bend angle from 150∘ to 45∘. Based on the finite element results, a simple collapse moment equation is proposed to predict the collapse moment for more accurate cross-section of the different angled pipe bends.


2021 ◽  
Vol 16 (2-3) ◽  
pp. 61-74
Author(s):  
Sahar Ghasemi ◽  
Amir Mirmiran ◽  
Yulin Xiao ◽  
Kevin Mackie

A super lightweight deck can enhance load rating and functionality of a bridge, especially those identified as structurally deficient. This study was aimed to develop and experimentally validate a novel bridge deck as an ultra-lightweight low-profile waffle slab of ultra-high-performance concrete (UHPC) with either carbon fiber reinforced polymer (CFRP) or high strength steel (HSS) reinforcement. The proposed system lends itself to accelerated bridge construction, rapid deck replacement in bridges with load restrictions, and bridge widening applications without the need to replace girders. Performance and failure modes of the proposed deck were initially assessed through extensive lab experiments and finite element analysis, which together confirmed that the proposed deck panel meets the AASHTO LRFD requirements. The proposed deck system is not susceptible to punching shear of its thin slab and fails in a rather ductile manner. To evaluate its long-term performance, the system was further tested under the dynamic impact of wheel load at the Accelerated Pavement Testing (APT) facility of the Florida Department of Transportation using a Heavy Vehicle Simulator (HVS).


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Shijun Chen ◽  
Qi Zhang ◽  
Surong Huang

To more efficiently design high performance vehicular permanent magnet motor, an electromagnetic-thermal integration design method is presented, which considers both the electromagnetic properties and the temperature rise of motor winding when determining the main dimensional parameters of the motor. Then a 48-slot and 8-pole vehicular permanent magnet motor is designed with this method. The thermomagnetic coupling design is simulated and validated on the basis of multiphysical domain on finite element analysis. Then the prototype is analyzed and tested on a newly built motor experiment platform. It is shown that the simulation results and experimental results are consistent, which validate the accuracy and effectiveness of the new design method. Also this method is proved to well improve the efficiency of permanent magnet motor design.


Author(s):  
Sergey Pisetskiy ◽  
Mehrdad Kermani

This paper presents an improved design, complete analysis, and prototype development of high torque-to-mass ratio Magneto-Rheological (MR) clutches. The proposed MR clutches are intended as the main actuation mechanism of a robotic manipulator with five degrees of freedom. Multiple steps to increase the toque-to-mass ratio of the clutch are evaluated and implemented in one design. First, we focus on the Hall sensors’ configuration. Our proposed MR clutches feature embedded Hall sensors for the indirect torque measurement. A new arrangement of the sensors with no effect on the magnetic reluctance of the clutch is presented. Second, we improve the magnetization of the MR clutch. We utilize a new hybrid design that features a combination of an electromagnetic coil and a permanent magnet for improved torque-to-mass ratio. Third, the gap size reduction in the hybrid MR clutch is introduced and the effect of such reduction on maximum torque and the dynamic range of MR clutch is investigated. Finally, the design for a pair of MR clutches with a shared magnetic core for antagonistic actuation of the robot joint is presented and experimentally validated. The details of each approach are discussed and the results of the finite element analysis are used to highlight the required engineering steps and to demonstrate the improvements achieved. Using the proposed design, several prototypes of the MR clutch with various torque capacities ranging from 15 to 200 N·m are developed, assembled, and tested. The experimental results demonstrate the performance of the proposed design and validate the accuracy of the analysis used for the development.


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