Analysis of thin-walled steel beams retrofitted by bonding GFRP stiffeners: Numerical model and investigation of design parameters

2017 ◽  
Vol 153 ◽  
pp. 166-179 ◽  
Author(s):  
Tuna Ulger ◽  
Ayman M. Okeil
Keyword(s):  
Numerical Model ◽  
Design Parameters ◽  
Steel Beams ◽  
Thin Walled

Softening behaviour of continuous thin-walled steel beams. Two numerical methods

1996 ◽  
Vol 36 (1) ◽  
pp. 1-13 ◽  
Author(s):  
K.T. Thomopoulos ◽  
E.S. Mistakidis ◽  
E.K. Koltsakis ◽  
P.D. Panagiotopoulos
Keyword(s):  
Numerical Methods ◽  
Steel Beams ◽  
Softening Behaviour ◽  
Thin Walled

scholarly journals Vibration and Instability of Rotating Composite Thin-Walled Shafts with Internal Damping

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ren Yongsheng ◽  
Zhang Xingqi ◽  
Liu Yanghang ◽  
Chen Xiulong
Keyword(s):  
Virtual Work ◽  
Numerical Study ◽  
Equations Of Motion ◽  
Beam Theory ◽  
Dynamical Analysis ◽  
Design Parameters ◽  
Internal Damping ◽  
Analysis Method ◽  
Governing Equations ◽  
Thin Walled

The dynamical analysis of a rotating thin-walled composite shaft with internal damping is carried out analytically. The equations of motion are derived using the thin-walled composite beam theory and the principle of virtual work. The internal damping of shafts is introduced by adopting the multiscale damping analysis method. Galerkin’s method is used to discretize and solve the governing equations. Numerical study shows the effect of design parameters on the natural frequencies, critical rotating speeds, and instability thresholds of shafts.

Experimental Investigations on Spot Welded Built-Up Cold-Formed Steel Beams

2018 ◽  
Vol 1146 ◽  
pp. 142-151
Author(s):  
Viorel Ungureanu ◽  
Ioan Both ◽  
Mircea Burca ◽  
Ştefan Benzar ◽  
Thai Hoang Nguyen ◽  
...  
Keyword(s):  
Spot Welding ◽  
Steel Sheet ◽  
Experimental Program ◽  
Experimental Investigations ◽  
Steel Beams ◽  
Technological Solution ◽  
Research Project ◽  
Steel Sheets ◽  
Cold Formed Steel ◽  
Thin Walled

Within the WELLFORMED research project, ongoing at the CEMSIG Research Center of the Politehnica University of Timisoara, a new technological solution was proposed for built-up beams made of corrugated steel sheets for the web and thin-walled cold-formed steel profiles for the flanges, connected by spot welding. The research project integrates an extensive experimental program on such beams, using full scale specimens, to demonstrate the feasibility of the proposed solutions and to assess their performance, followed by numerical simulations to characterize and optimize the connecting details. The present paper presents the results of a large experimental program, on small specimens subjected to shear, consisting of two or three layers of steel sheet connected by spot welding.

scholarly journals Dynamic Impedances of Offshore Rock-Socketed Monopiles

2019 ◽  
Vol 7 (5) ◽  
pp. 134 ◽  
Author(s):  
Rui He ◽  
Ji Ji ◽  
Jisheng Zhang ◽  
Wei Peng ◽  
Zufeng Sun ◽  
...  
Keyword(s):  
Numerical Model ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Dynamic Stiffness ◽  
Large Diameter ◽  
Offshore Wind ◽  
Offshore Wind Turbines ◽  
Thin Walled ◽  
Rock Parameters ◽  
Radiative Damping

With the development of offshore wind energy in China, more and more offshore wind turbines are being constructed in rock-based sea areas. However, the large diameter and thin-walled steel rock-socketed monopiles are very scarce at present, and both the construction and design are very difficult. For the design, the dynamic safety during the whole lifetime of the wind turbine is difficult to guarantee. Dynamic safety of a turbine is mostly controlled by the dynamic impedances of the rock-socketed monopile, which are still not well understood. How to choose the appropriate impedances of the socketed monopiles so that the wind turbines will neither resonant nor be too conservative is the main problem. Based on a numerical model in this study, the accurate impedances are obtained for different frequencies of excitation, different soil and rock parameters, and different rock-socketed lengths. The dynamic stiffness of monopile increases, while the radiative damping decreases as rock-socketed depth increases. When the weathering degree of rock increases, the dynamic stiffness of the monopile decreases, while the radiative damping increases.

scholarly journals Optimization of flat-oval pipes and perspectives of their application in beam structures

2018 ◽  
Vol 251 ◽  
pp. 03016
Author(s):  
Alexander Marutyan ◽  
Tamazi Kobaliya ◽  
Evgeny Galdin
Keyword(s):  
Cross Sections ◽  
Bending Strength ◽  
Low Cost ◽  
Design Parameters ◽  
Technical Solution ◽  
Optimal Parameters ◽  
Resistance Moment ◽  
Thin Walled ◽  
Lower Height ◽  
Oval Shape

A new technical solution for re-profiling round tubes into flat-oval ones with a ratio of 1 / 3,064 is presented, which increases their bending strength. The calculation of the optimal parameters of thin-walled sections of the flat-oval shape is given by an approximate method, the correctness of which is confirmed by testing from the standard profiles used. This calculation is repeated with respect to thin-walled sections of the oval shape. The whole diagram of changes in the design parameters of flat-oval and oval pipes is presented in the transformation of their cross-sections from vertical configurations to horizontal ones, including the transition through the outline of a circular shape. The comparative analysis of optimized cross sections of flat oval, oval and round tubes is carried out taking into account the elastic and elastic-plastic deformations of the structural material, where the length of the midline of the thin-walled section is taken as the dividing line between these deformations. The choice is substantiated in favour of flat-oval profile pipes due to their simpler shape including faces of constant curvature (flat and semi-circular), relatively low cost, lower height, greater compactness, higher resistance moment.

scholarly journals On Problem of Torsional Characteristics of Thin-walled Steel Beams with Web Openings

2019 ◽  
Vol 471 ◽  
pp. 052040
Author(s):  
Martin Horacek ◽  
Jindrich Melcher ◽  
Ivan Balazs ◽  
Ondrej Pesek
Keyword(s):  
Steel Beams ◽  
Web Openings ◽  
Thin Walled

A FEA Simulation Model for Thin-Walled C-Section Composite Beam Assembling With R-Angle Deviation

2014 ◽  
Author(s):  
Hua Wang ◽  
Suo Si
Keyword(s):  
Numerical Model ◽  
Composite Beam ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Element Model ◽  
Load Level ◽  
Compression Tests ◽  
Accurate Analysis ◽  
Angle Deviation ◽  
Thin Walled

There are unavoidable deviations, such as shrinkage and distortions, in the composite detail parts production due to the complexity of composites fabrication. Interests in the assembly analysis of composite beams have led to a need for more accurate analysis especially in the case of fabrication deviations. This work proposes a numerical finite element model of thin-walled C-section composite beam with R-angle deviation for assembling. The rule of Hashin failure combined with cohesive element is applied to study the mechanical performance of the fiber and matrix (implemented as user subroutine UMAT in ABAQUS) while positioning and clamping. Tension and compression tests are carried out based on available standards to determine the C-section beam behavior under load. The testing data validates the proposed numerical model. The numerical model captures the experimentally obtained results with minimal error, and predicts the failure modes successfully. The proposed model allows to determine accurately the first failure location and the associated load level. It will enhance the understanding of the composite components pre-loading analysis, and help systematically improving the composites assembling efficiency in civil aircraft industry.

scholarly journals Partially-Encased Composite Thin-Walled Steel Beams

2012 ◽  
Vol 40 ◽  
pp. 91-95 ◽  
Author(s):  
V. Kvočáka ◽  
L. Drab
Keyword(s):  
Steel Beams ◽  
Thin Walled

Numerical and Experimental Studies of Ballistic Compression Process in a Soft Recovery System

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Girijesh Mathur ◽  
Nachiketa Tiwari ◽  
Neha Chaturvedi
Keyword(s):  
Experimental Data ◽  
Numerical Model ◽  
Experimental Studies ◽  
Pressure Rise ◽  
Sensitivity Analyses ◽  
Design Parameters ◽  
Strong Positive Correlation ◽  
Compression Process ◽  
Recovery System ◽  
Two Parameters

Abstract A ballistic compression type soft recovery system can stop a free-flying supersonic projectile in a controlled manner. The moment such a projectile enters the System, a normal shock gets created and starts hurtling down, to kick off a train of events involving shock reflections, diaphragm rupture, shock merger, creation of new shocks and contact discontinuities, and expansion wave-shock interactions. A good understanding of these phenomena and sensitivity of the System's performance to changes in design parameters is needed to design an efficient soft recovery system. Unfortunately, not much information is available about this. The present work fills this gap. We have developed a numerical model for the system and conducted sensitivity analyses using four design parameters; pressure, molecular weight, the ratio of specific heats, and temperature of gas used in the system. We show that while there is a strong, positive correlation between the first two parameters and projectile deceleration, the other two parameters are less critical. We conducted experiments to corroborate our conclusions and improve our numerical model. Post such improvements, we found the difference between simulation and experimental data to be acceptable. Experiments also confirmed the findings of our sensitivity studies. Finally, we conducted a two-dimensional finite volume analysis to understand the reasons underlying the residual difference between our numerical and experimental data. We show that such differences are due to pressure-rise at a point once a shock passes by it, and such a rise in pressure is attributable to boundary layer effects.

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