Finite Element Analysis on Plastic Deformation Behaviors of Ti-3Al-2.5V Tubes under Axial Compression

2015 ◽  
Vol 639 ◽  
pp. 551-558 ◽  
Author(s):  
Tao Huang ◽  
Mei Zhan ◽  
Jin Qiang Tan ◽  
Jing Guo ◽  
He Yang

With the requirement of aviation and aerospace fields for high-strength Ti-3Al-2.5V titanium alloy bent tubes with high-performance, it is great significance to research the plastic deformation of Ti-3Al-2.5V tubes under compression to obtain desired flow stress curves. A finite element (FE) model of axial compression of Ti-3Al-2.5V tubes was established in this study. Using this model, deformation behaviors of Φ12 mm × t0.9 mm Ti-3Al-2.5V tubes with different ratios of thickness to height (t/h) compressed under different frictions were analyzed. It is shown that the non-uniform deformation degree of the tubes increases with the decrease of t/h and the increase of friction coefficient. This means that a large t/h value and small friction can help to attain a uniaxial compression condition to obtain desired flow stress curves. Such compression conditions for the Φ12 mm × t0.9 mm Ti-3Al-2.5V tube is that, t/h is not less than 0.6 and the friction coefficient is not greater than 0.05

Author(s):  
V. S. N. Ranjith Kumar ◽  
S. Kumar ◽  
G. Pal ◽  
Tushar Shah

Design of high-performance power lines with advanced materials is indispensable to effectively eliminate losses in electrical power transmission and distribution (T&D) lines. In this study, aluminum conductor composite core with carbon nanostructure (ACCC–CNS) coating in a multilayered architecture is considered as a novel design alternative to conventional aluminum conductor steel-reinforced (ACSR) transmission line. In the multiphysics approach presented herein, first, electrothermal finite element analysis (FEA) of the ACSR line is performed to obtain its steady-state temperature for a given current. Subsequently, the sag of the ACSR line due to self-weight and thermal expansion is determined by performing thermostructural analysis employing an analytical model. The results are then verified with those obtained from the FEA of the ACSR line. The electrothermal finite element (FE) model and the thermostructural analytical model are then extended to the ACCC–CNS line. The results indicate that the ACCC–CNS line has higher current-carrying capacity (CCC) and lower sag compared to those of the ACSR line. Motivated by the improved performance of the ACCC–CNS line, a systematic parametric study is conducted in order to determine the optimum ampacity, core diameter, and span length. The findings of this study would provide insights into the optimal design of high-performance overhead power lines.


Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3540
Author(s):  
Fengky Satria Yoresta ◽  
Phan Viet Nhut ◽  
Yukihiro Matsumoto

This paper presented a non-linear finite element (FE) analysis to investigate the potential of unbonded carbon fiber-reinforced polymers (CFRP) strengthening in improving the axial compression performance of steel members. The FE model was firstly developed and validated against experimental works. Four parameters considered in the parametric study were the number of CFRP layers, CFRP length, slenderness ratio, and elastic modulus of CFRP. It was confirmed that the unbonded CFRP strengthening method is effective at enhancing the load-carrying capacity as well as delaying the overall buckling of the axial steel members. The strength increase is highly affected by the first three parameters. In addition, the method of an equivalent slenderness ratio can be used for strength design.


2018 ◽  
Vol 2 (4) ◽  
pp. 83 ◽  
Author(s):  
Brigit Mittelman ◽  
Elad Priel ◽  
Nissim Navi

The most accepted method for determining friction conditions in metal forming is the ring compression test (RCT). At high temperatures, extraction of the friction coefficient, μ, commonly requires numerical analysis due to the coupling between the mechanical and thermal fields. In the current study, compression tests of cylindrical specimens and RCT experiments were conducted on commercially pure aluminium (Al1050) at several temperatures, loading rates, and lubrication conditions. The experiments were used in conjunction with a coupled thermo-mechanical finite element analysis to study the dependence of the friction coefficient on those parameters. It is demonstrated that due to the coupling between friction conditions and material flow stress, both μ and flow stress data should be determined from the cylinder and ring specimens simultaneously and not subsequently. The computed friction conditions are validated using a novel method based on identification of the plastic flow neutral radius. It is shown that, due to heat loss mechanisms, the experimental system preparation stage must be incorporated in the computational analysis. The study also addresses the limitation of the RCT in the presence of high friction conditions. The computational models are finally used to examine the thermo-mechanical fields, which develop during the different processes, with an emphasis on the effect of friction conditions, which were then correlated to the resulting microstructure in the RCTs.


Author(s):  
Ashwini Gautam ◽  
Chris Fuller ◽  
James Carneal

This work presents an extensive analysis of the properties of distributed vibration absorbers (DVAs) and their effectiveness in controlling the sound radiation from the base structure. The DVA acts as a distributed mass absorber consisting of a thin metal sheet covering a layer of acoustic foam (porous media) that behaves like a distributed spring-mass-damper system. To assess the effectiveness of these DVAs in controlling the vibration of the base structures (plate) a detailed finite elements model has been developed for the DVA and base plate structure. The foam was modeled as a poroelastic media using 8 node hexahedral elements. The structural (plate) domain was modeled using 16 degree of freedom plate elements. Each of the finite element models have been validated by comparing the numerical results with the available analytical and experimental results. These component models were combined to model the DVA. Preliminary experiments conducted on the DVAs have shown an excellent agreement between the results obtained from the numerical model of the DVA and from the experiments. The component models and the DVA model were then combined into a larger FE model comprised of a base plate with the DVA treatment on its surface. The results from the simulation of this numerical model have shown that there has been a significant reduction in the vibration levels of the base plate due to DVA treatment on it. It has been shown from this work that the inclusion of the DVAs on the base plate reduces their vibration response and therefore the radiated noise. Moreover, the detailed development of the finite element model for the foam has provided us with the capability to analyze the physics behind the behavior of the distributed vibration absorbers (DVAs) and to develop more optimized designs for the same.


Author(s):  
Serafino Caruso ◽  
Stano Imbrogno

AbstractGrain refinement by severe plastic deformation (SPD) techniques, as a mechanism to control microstructure (recrystallization, grain size changes,…) and mechanical properties (yield strength, ultimate tensile strength, strain, hardness variation…) of pure aluminium conductor wires, is a topic of great interest for both academic and industrial research activities. This paper presents an innovative finite element (FE) model able to describe the microstructural evolution and the continuous dynamic recrystallization (CDRX) that occur during equal channel angular drawing (ECAD) of commercial 1370 pure aluminium (99.7% Al). A user subroutine has been developed based on the continuum mechanical model and the Hall-Petch (H-P) equations to predict grain size variation and hardness change. The model is validated by comparison with the experimental results and a predictive analysis is conducted varying the channel die angles. The study provides an accurate prediction of both the thermo-mechanical and the microstructural phenomena that occur during the process characterized by large plastic deformation.


2021 ◽  
pp. 136943322110015
Author(s):  
Rana Al-Dujele ◽  
Katherine Ann Cashell

This paper is concerned with the behaviour of concrete-filled tubular flange girders (CFTFGs) under the combination of bending and tensile axial force. CFTFG is a relatively new structural solution comprising a steel beam in which the compression flange plate is replaced with a concrete-filled hollow section to create an efficient and effective load-carrying solution. These members have very high torsional stiffness and lateral torsional buckling strength in comparison with conventional steel I-girders of similar depth, width and steel weight and are there-fore capable of carrying very heavy loads over long spans. Current design codes do not explicitly include guidance for the design of these members, which are asymmetric in nature under the combined effects of tension and bending. The current paper presents a numerical study into the behaviour of CFTFGs under the combined effects of positive bending and axial tension. The study includes different loading combinations and the associated failure modes are identified and discussed. To facilitate this study, a finite element (FE) model is developed using the ABAQUS software which is capable of capturing both the geometric and material nonlinearities of the behaviour. Based on the results of finite element analysis, the moment–axial force interaction relationship is presented and a simplified equation is proposed for the design of CFTFGs under combined bending and tensile axial force.


Author(s):  
Constantine M. Tarawneh ◽  
Arturo A. Fuentes ◽  
Javier A. Kypuros ◽  
Lariza A. Navarro ◽  
Andrei G. Vaipan ◽  
...  

In the railroad industry, distressed bearings in service are primarily identified using wayside hot-box detectors (HBDs). Current technology has expanded the role of these detectors to monitor bearings that appear to “warm trend” relative to the average temperatures of the remainder of bearings on the train. Several bearings set-out for trending and classified as nonverified, meaning no discernible damage, revealed that a common feature was discoloration of rollers within a cone (inner race) assembly. Subsequent laboratory experiments were performed to determine a minimum temperature and environment necessary to reproduce these discolorations and concluded that the discoloration is most likely due to roller temperatures greater than 232 °C (450 °F) for periods of at least 4 h. The latter finding sparked several discussions and speculations in the railroad industry as to whether it is possible to have rollers reaching such elevated temperatures without heating the bearing cup (outer race) to a temperature significant enough to trigger the HBDs. With this motivation, and based on previous experimental and analytical work, a thermal finite element analysis (FEA) of a railroad bearing pressed onto an axle was conducted using ALGOR 20.3™. The finite element (FE) model was used to simulate different heating scenarios with the purpose of obtaining the temperatures of internal components of the bearing assembly, as well as the heat generation rates and the bearing cup surface temperature. The results showed that, even though some rollers can reach unsafe operating temperatures, the bearing cup surface temperature does not exhibit levels that would trigger HBD alarms.


2011 ◽  
Vol 374-377 ◽  
pp. 2430-2436
Author(s):  
Gang Shi ◽  
Zhao Liu ◽  
Yong Zhang ◽  
Yong Jiu Shi ◽  
Yuan Qing Wang

High strength steel sections have been increasingly used in buildings and bridges, and steel angles have also been widely used in many steel structures, especially in transmission towers and long span trusses. However, high strength steel exhibits mechanical properties that are quite different from ordinary strength steel, and hence, the local buckling behavior of steel equal angle members under axial compression varies with the steel strength. However, there is a lack of research on the relationship of the local buckling behavior of steel equal angle members under axial compression with the steel strength. A finite element model is developed in this paper to analyze the local buckling behavior of steel equal angle members under axial compression, and study its relationship with the steel strength and the width-to-thickness ratio of the angle leg. The finite element analysis (FEA) results are compared with the corresponding design method in the American code AISC 360-05, which provides a reference for the related design.


2007 ◽  
Vol 539-543 ◽  
pp. 2651-2656 ◽  
Author(s):  
C.J. Huang ◽  
E. Ghassemieh

A 3-D coupled temperature-displacement finite element analysis is performed to study an ultrasonic consolidation process. Results show that ultrasonic wave is effective in causing deformation in aluminum foils. Ultrasonic vibration leads to an oscillating stress field. The oscillation of stress in substrate lags behind the ultrasonic vibration by about 0.1 cycle of ultrasonic wave. The upper foil, which is in contact with the substrate, has the most severe deformation. The substrate undergoes little deformation. Apparent material softening by ultrasonic wave, which is of great concern for decades, is successfully simulated. The higher the friction coefficient, the more obvious the apparent material softening effect.


2013 ◽  
Vol 671-674 ◽  
pp. 1025-1028
Author(s):  
Dong Ku Shin ◽  
Kyungsik Kim

The ultimate compressive strengths of high performance steel (HPS) plate system stiffened longitudinally by closed stiffeners have been investigated by the nonlinear finite element analysis. Both conventional and high performance steels were considered in models following multi-linear strain hardening constitutive relationships. Initial geometric imperfections and residual stresses were also incorporated in the analysis. Numerical results have been compared to compressive strengths from Eurocode 3 EN 1993-1-5 and FHWA-TS-80-205. It has been found that although use of Eurocode 3 EN 1993-1-5 and FHWA-TS-80-205 may lead to highly conservative design strengths when very large column slenderness parameters are encountered


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