scholarly journals ADHESIVES IN STRENGTHENING OF STEEL STRUCTURES

2010 ◽  
Vol 2 (2) ◽  
pp. 45-50 ◽  
Author(s):  
Hartmut Pasternak ◽  
Gabriel Kubieniec ◽  
Marek Piekarczyk

This study includes a detailed analysis of using adhesives in reinforcement of steel structures. Two types of structures were experimentally investigated: box girder and knee joints. The numerical calculations were done on the basis of the experimental investigations performed at CUT Cracow (box girder) and BTU Cottbus (knee joints) with the use of numerical programme Abaqus based on the Finite Element Method. The numerical results were compared with the experimental ones.

2008 ◽  
Vol 45 (3) ◽  
pp. 393-407
Author(s):  
Chun Fai Leung ◽  
Rui Fu Shen

Gravity caissons were employed as part of the wharf front structures for a container port terminal in Singapore. This paper reports the movements of eight consecutive gravity caissons supported on sand compaction piles (SCPs) with highly variable lengths of penetration. It is established that the caisson movements increase with an increase in the length of the SCP, as longer SCPs are necessary when hard strata are at greater depth. The large caisson movements observed during caisson infilling and backfilling do not pose a concern because the wharf deck beams connecting adjacent caissons can be adjusted. However, the caisson movements under service loads would affect the operation of the overlying quay cranes on top of the caissons. The present field study reveals that preloading the caissons is effective in reducing the caisson movements under service loads because the observed caisson movements are insignificant during subsequent unloading–reloading of the caissons. Back-analysis using the finite element method (FEM) shows that the observed caisson movements at different construction stages can be reasonably replicated. The numerical results are also used to evaluate the caisson tilt angle, which could not be measured in the present field study. The caisson tilt is found to be independent of the length of SCPs underneath a caisson.


2011 ◽  
Vol 250-253 ◽  
pp. 3872-3875
Author(s):  
Rong Jian Li ◽  
Wen Zheng ◽  
Juan Fang ◽  
Gao Feng Che

The influence of structural strength on the lining moment of tunnel should be properly evaluated in order to meet the engineering demand in loess area. It is essential to analyze and evaluate the lining moment of tunnel by means of the finite element method under the condition of the different local weakening of structural strength in loess. Firstly, some researches on the structural strength of loess tunnel are reviewed. Then, some different cases of the local weakening of structural strength in loess are analyzed in this paper. Numerical results not only indicate that the lining moment of tunnel tends to change obviously with the different local weakening of the structural strength, but also reveal that the weakening location of structural strength has important effect on the distribution and redistribution of the lining moment of tunnel.


2021 ◽  
Vol 2117 (1) ◽  
pp. 012002
Author(s):  
A Y Ismail ◽  
B Y Koo

Abstract Harmonic wave propagation through a novel metasurface design is presented in this paper. The metasurface is formed by using the Helmholtz resonator as the cells shape design since such resonator has uniqueness and advantageous performances. The study is conducted both numerically using the finite element method and experimentally using specific measurements to validate the numerical results. Parametric studies of the selected variables are also conducted to obtain broader information on the performance. From the result, it is found that the new proposed metasurface design has the potential to be implemented in future engineering practices.


2020 ◽  
Vol 7 (10) ◽  
pp. 458-470
Author(s):  
Benício de Morais Lacerda ◽  
Alex Gomes Pereira

This study aimed to investigate numerically the validation of the use of the free license program Code_ Aster, with numerical results of the SolidWorks program. For this, four metal elements were modeled, all of them subjected to the tensile stress, they are: a cylindrical bar, two plates with a hole and a metal console. The objective is to validate the use of a free program for analysis of structural elements in engineering office projects and institutional research to verify if the results obtained from the free program show significant differences in the numerical application of a commercial program. All programs have in their design of analysis the use of the finite element method (FEM). The finite element method (FEM) consists to divide a continuous object into a finite number of parts. This allows a complex problem to be transformed into a set of simple problems (finite element) in addition to solving a set of finite elements by approximations with good precision of the results and to model the problem in a real physical way. It was observed that the numerical results between the SolidWorks program and the free program Code_ Aster were close with differences of less than 5%, which indicates the reliability of the use of Code_ Aster for numerical analyzes of structural elements of engineering projects and also in institutional research.


Author(s):  
R Safdarian

The tube wrinkling, ovality, and fracture are the main defects in the rotary draw bending process, which happen by incorrect selection of process parameters. In the present study, the wrinkling, fracture, and ovality of BS 3059 steel tube in the rotary draw bending were investigated using the experimental tests and the finite element method. The numerical results were verified using the experimental tests for tube ovality prediction. The tube fracture was predicted using the Gurson–Tvergaard–Needleman damage model in the rotary draw bending numerical simulations. The design of experiment based on the response surface method and the finite element method was used to investigate the effects of rotary draw bending parameters such as boosting velocity of pressure die, mandrel position, number of balls, and pressure of pressure die on the wrinkling, fracture, and tube ovality. The experimental and numerical results indicated that the mandrel position was one of the main parameters, which influence the tube ovality. The tube ovality and wrinkling increased with the increase in the mandrel position.


Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2279
Author(s):  
Leszek Czechowski ◽  
Gabriela Kmita-Fudalej ◽  
Włodzimierz Szewczyk

This work concerns the analysis of egg packages subjected to compression. Experimental investigations were carried out to determine the curves of compression and maximum loads. To compare packages accessible on the market, several different shapes of egg packages were tested after being conditioned in air with a relative humidity of 50%. Several paper structures in stock were compressed. By validating the experiment results, numerical computations based on the finite element method (FEM) were executed. The estimations of a numerical model were performed with the use of the perfect plasticity of paper and with the assumption of large strains and deflections. Our own two structures of egg packaging were taken into account: basic and modified. The material of the packages was composed of 90% recovered paper and 10% coconut fibres. This paper involved the numerical modelling of such complex packaging. Moreover, our research showed that introducing several features into the structures of the packaging can improve the stiffness and raise the maximum load. Thanks to the application of ribs and grooves, the strength ratio and compression stiffness, in comparison to the basic tray, increased by approximately 23.4% and 36%, respectively. Moreover, the obtained indexes of modified trays were higher than the majority of the studied market trays.


Author(s):  
S Feng ◽  
HP Geng ◽  
L Yu

A quill-shaft coupling-rotor-bearing system is modeled and reported in this paper. The system consists of two rotors connected by a quill-shaft coupling in which each rotor is supported by two bearings. The stiffness matrix of the quill-shaft coupling is deduced and the equation of motion of the system is obtained by using the finite element method. Finally, the rotordynamics analysis of the system is conducted. The numerical results show that more frequency veering points occur for the quill-shaft coupling-rotor-bearing system compared with those of single rotor. In addition, the stiffness of the flexural element has significant effects on the first bending natural frequency of the quill shaft when the length of the quill shaft becomes shorter.


Author(s):  
P Hernandez ◽  
R Boudet

The objective of this paper is to present a model of the behaviour of dynamical seals and the corresponding numerical results. These seals are used in the mechanism to realize partial sealing when the relative rotating speeds are too high for usual solutions. The studied seals mainly include two discs: one is attached to the shaft and the other to the body, the last one being pushed and the first being attached by springs. During operation, a gaseous film is created between the discs, preventing any contact. The control of the film thickness allows the leakage flow to be controlled. For the behaviour of such mechanisms, an analytical formulation of the problem is firstly presented. Then a geometrical and kinematical model having one degree of freedom is proposed to model the mechanism having two discs in relative rotation, one of which is spirally grooved. A dynamical model associated with the motion of the disc attached to the body has been developed and the mechanics of thin viscous films is used to study the behaviour of the gaseous film at the interface. Utilization of the finite element method in the mechanics of thin viscous films is introduced and a description of the elements used is presented. The influence of the groove's angle and the groove's depth is shown through numerical results concerning leakage mass flow through the mechanism and the loading capacity of the fluid film, as well as the coefficients of stiffness and damping associated with the dynamical model.


2012 ◽  
Vol 204-208 ◽  
pp. 3236-3239 ◽  
Author(s):  
Wen Xiong Huang ◽  
Li Ying Tan

Based on the real construction technology, process and environment of Yuquanxi Bridge, the finite element method was applied in the research to make sure the crack mechanism and find out the impact of improper construction procedure on cracks of Block No.0. By comparing the numerical results with actual cracks condition, the impact of improper construction procedure on cracks of Block No.0 is uncovered clearly and it proves that to master of correct construction procedures and methodology is of great importance in construction a bridge.


2015 ◽  
Vol 37 (4) ◽  
pp. 47-55
Author(s):  
Eugeniusz Sawicki ◽  
Tomasz Strzelecki

Abstract This article presents the results of numerical calculations of soil consolidation underneath the “Africa Pavilion” structure in Wrocław Zoo, Poland. To determine the deformations of the baseplate of the “Africa Pavilion” and deformations of the subsoil, Biot’s consolidation theory for two-phase medium was applied. The calculations were carried out using the professional program FlexPDE v.6, which is based on the Finite Element Method. Numerical calculations performed were used to evaluate the design assumptions allowing for the laying of hydraulic conduits under the slab.


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