scholarly journals Numerical Analysis of Friction Effects on Temperature and Phases within Forged Ti-6Al-4V Alloy Aeroengine Drum

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1649
Author(s):  
Shiyuan Luo ◽  
Yongxin Jiang ◽  
Kai Yan ◽  
Guangming Zou ◽  
Po Zhang ◽  
...  

Friction conditions significantly impact the temperature and phases of titanium forged parts, further directly affecting the microstructures and mechanical properties of final parts. In this paper, a 2D simplified finite element (FE) model combined with phase transition equations is developed to simulate a Ti-6Al-4V drum forging procedure. Then, friction effects on the temperature and phases of the forged drum are numerically analyzed and verified by experiments. The simulated results indicate that a reasonable range of friction factor is needed to obtain a relatively homogenous temperature distribution within the forged drum. Moreover, unlike its small influence on the α + β phase, improving friction obviously decreases the general levels of temperature and β phase and increases the homogeneities of α and β phases within the forged drum, which are associated with cooling rates and the heating effects of friction and deformation.

2021 ◽  
Author(s):  
Shiyuan Luo ◽  
Yongxin Jiang ◽  
Po Zhang ◽  
Fengping Yu ◽  
Siwen Liu

Abstract Friction conditions significantly impact the temperature and phases of titanium forged parts, further directly affecting the microstructures and mechanical properties of final parts. In this paper, a 2D simplified FE model combined with phase transition equations is developed to simulate Ti-6Al-4V drum forging procedure. Then, friction effects on the temperature and phases of the forged drum are numerically analyzed and verified by experiments. Results indicate that unlike little influence on α+β phase, improving friction obviously decreases the general levels of temperature and β phase and increases the homogeneities of α and β phases within the forged drum, which are associated with cooling rates and the heating effects of friction and deformation.


Vibration ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 151-174
Author(s):  
André F. S. Rodrigues ◽  
Zuzana Dimitrovová

In this paper, the three-layer model of ballasted railway track with discrete supports is analyzed to access its applicability. The model is referred as the discrete support model and abbreviated by DSM. For calibration, a 3D finite element (FE) model is created and validated by experiments. Formulas available in the literature are analyzed and new formulas for identifying parameters of the DSM are derived and validated over the range of typical track properties. These formulas are determined by fitting the results of the DSM to the 3D FE model using metaheuristic optimization. In addition, the range of applicability of the DSM is established. The new formulas are presented as a simple computational engineering tool, allowing one to calculate all the data needed for the DSM by adopting the geometrical and basic mechanical properties of the track. It is demonstrated that the currently available formulas have to be adapted to include inertial effects of the dynamically activated part of the foundation and that the contribution of the shear stiffness, being determined by ballast and foundation properties, is essential. Based on this conclusion, all similar models that neglect the shear resistance of the model and inertial properties of the foundation are unable to reproduce the deflection shape of the rail in a general way.


2015 ◽  
Vol 651-653 ◽  
pp. 225-230 ◽  
Author(s):  
Antonino Ducato ◽  
Gianluca Buffa ◽  
Antonello Astarita ◽  
Antonino Squillace ◽  
Livan Fratini ◽  
...  

Titanium forging has been encountering a growing interest in the scientific and industrial communities because of the distinct advantages it provides with respect to machining, in terms of both mechanical properties of the product and material waste, thus significantly reducing the Buy to Fly ratio. In the paper, a numerical FE model, based on a tri-coupled approach and able to predict the microstructural evolutions of the workpiece during the process, is developed and set up. Calculated results are compared to experiments for a few industrial case studies. The final phases distribution in the forged parts is experimentally measured and compared to the FE model output finding satisfying overlapping.


2010 ◽  
Vol 654-656 ◽  
pp. 739-742 ◽  
Author(s):  
Kenichi Manabe ◽  
Toshiji Morishima ◽  
Yu Ogawa ◽  
Kazuo Tada ◽  
Tsutomu Murai ◽  
...  

In this study, non-uniform heating approach in warm T-joint forming process is attempted for the AZ31 magnesium alloy tube. For this purpose, finite element simulation is performed to analyze the appropriate temperature distribution. The validity of the finite element(FE) model of T-joint tube hydroforming(THF) is verified by comparing the FE simulation and experimental results. Using this FE model, appropriate temperature distribution was suggested. In addition, it was showed that the wall thickness could be more uniform by optimizing the temperature condition.


2015 ◽  
Vol 661 ◽  
pp. 91-97
Author(s):  
Cho-Pei Jiang ◽  
Zong Han Huang

The aim of this research is to investigate the effect of grain size on the mechanical properties and deformability of titanium alloy in equal channel and cross-sectional reduction channel angular pressing process. Specimens made of grade 2 titanium alloy with diameter 5 mm are annealed to temperature of 500 °C to 1000 °C resulting in different initial grain sizes, thus underwent tensile test for obtaining mechanical properties. Molds for both processes are designed to carry out serve plastic deformation. Finite element models are created and simulated the deformation behavior according to the mechanical properties of tensile test. Experimental results show that small α-phase grain starts to form in 700 °C homogenization treatment and its grain size increases as an increasing of annealing temperature. The β-phase microstructure precipitates resulting in brittle behavior in 850 °C annealing treatment. Simulation result show that squeeze load of ECAP is larger than 100 ton but it can be reduced when exit angle of channel is larger than entrance. Outer corner of ECAP with 90 ̊ generate lower squeeze pressure than that of 40 ̊.


2020 ◽  
Vol 14 (54) ◽  
pp. 169-181
Author(s):  
Pan Jinlong ◽  
Li Guanhua ◽  
Jingming Cai

In this paper, the finite element (FE) method was used to investigate the axial compressive behaviors of circular and square concrete filled aluminum tubes (CFAT). Firstly, the simulational results were compared with the experimental results and the accuracy of the proposed FE model was verified. On this basis, the FE model was further applied to compare the mechanical properties of both circular and square CFATs under axial compression. It was found that the circular CFATs have a better effect on restraining the core concrete than square CFATs. The parametric analysis was also conducted based on the proposed FE model. It was noticed that the mechanical differences of the two kinds of CFATs gradually decreased with the increase of the aluminum ratio, aluminum strength and concrete strength.


2008 ◽  
Author(s):  
Jonathan Vappou

A large number of pathological conditions result in significant changes of the mechanical properties of the aortic wall. Using the Pulse Wave Velocity (PWV) as an indicator of aortic stiffness has been proposed for several decades. Pulse Wave Imaging (PWI) is an ultrasonography-based imaging method that has been developed to map and quantify the pulse wave (PW) propagation along the abdominal aortic wall and measure its local properties. We present a finite-element-based approach that aims at improving our understanding of the complex PW patterns observed by PWI and their relationship to the underlying mechanical properties. A Fluid-Structure Interaction (FSI) coupled model was developed based on an idealized axisymmetric aorta geometry. The accuracy of the model as well as its ability to reproduce realistic PW propagation were evaluated by performing a parametric analysis on aortic elasticity, by varying the aortic Young�s modulus between 20 kPa and 2000 kPa. The Finite-Element model was able to predict with good accuracy the expected PWV values in different theoretical cases, with an averaged relative difference of 14% in the 20kPa-100kPa, which corresponds to a wide physiologic range for stiffness of the healthy aorta. This study allows to validate the proposed FE model as a tool that is capable of representing quantitatively the pulse wave patterns in the aorta.


Author(s):  
Ali Vahdati ◽  
Diane R. Wagner

Articular cartilage (AC) disease and especially osteoarthrithis (OA) are debilitating conditions that are associated with huge social and economic burdens. To understand the factors involved in initiation and progression of OA, the mechanical state of the cartilage tissue must be first understood [1]. Biphasic and triphasic models developed by Mow and coworkers relate AC structure with its mechanical behavior and provided researchers with valuable models for AC biomechanics [2, 3]. Although much is known about AC and its mechanical properties, the zone of calcified cartilage (ZCC) has been sparsely studied. ZCC is very thin and highly interdigitated with subchondral bone (SB) which makes it very difficult to isolate for independent study [4]. It is well known that SB plays an important role in both initiation and/or progression of OA [5], thus ZCC may also be an important player in the pathology of the disease [6]. A few studies have investigated mechanical properties of ZCC, but conflicting results have been published on ZCC permeability. Although ZCC has been mainly assumed to be impermeable [7], recently Hwang et al. [8] suggested that ZCC may have even higher permeability than cartilage itself. We studied the effect of ZCC permeability on mechanical behavior of AC using a finite element (FE) model.


2004 ◽  
Vol 19 (1) ◽  
pp. 338-346 ◽  
Author(s):  
D.M. Follstaedt ◽  
J.A. Knapp ◽  
S.M. Myers

We used nanoindentation coupled with finite element modeling to determine the mechanical properties of amorphous Si layers formed by self-ion implantation of crystalline Si at approximately 100 K. When the effects of the harder substrate on the response of the layers to indentation were accounted for, the amorphous phase was found to have a Young’s modulus of 136 ± 9 GPa and a hardness of 10.9 ± 0.9 GPa, which were 19% and 10% lower than the corresponding values for crystalline Si. The hardness agrees well with the pressure known to induce a phase transition in amorphous Si to the denser β–Sn-type structure of Si. This transition controls the yielding of amorphous Si under compressive stress during indentation, just as it does in crystalline Si. After annealing 1 h at 500 °C to relax the amorphous structure, the corresponding values increase slightly to 146 ± 9 GPa and 11.6 ± 1.0 GPa. Because hardness and elastic modulus are only moderately reduced with respect to crystalline Si, amorphous Si may be a useful alternative material for components in Si-based microelectromechanical systems if other improved properties are needed, such as increased fracture toughness.


Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2487
Author(s):  
Mohammad J. Ghasemi Parizi ◽  
Hossein Shahverdi ◽  
Ehsan Pipelzadeh ◽  
Andreu Cabot ◽  
Pablo Guardia

Glass-fiber-reinforced polymer (GFRP) composites represent one of the most exploited composites due to their outstanding mechanical properties, light weight and ease of manufacture. However, one of the main limitations of GFRP composites is their weak inter-laminar properties. This leads to resin delamination and loss of mechanical properties. Here, a model based on finite element analysis (FEA) is introduced to predict the collective advantage that a GF surface modification has on the inter-laminar properties in GFRP composites. The developed model is validated with experimental pull-out tests performed on different samples. As such, modifications were introduced using different surface coatings. Interfacial shear stress (IFSS) for each sample as a function of the GF to polymer interphase was evaluated. Adhesion energy was found by assimilating the collected data into the model. The FE model reported here is a time-efficient and low-cost tool for the precise design of novel filler interphases in GFRP composites. This enables the further development of novel composites addressing delamination issues and the extension of their use in novel applications.


Sign in / Sign up

Export Citation Format

Share Document