scholarly journals Finite Element Analysis and Investigation on Spinning of Quadrilateral Parts with Hollow Cross-Sections Based on Hypocycloid Theory

2020 ◽  
Vol 10 (23) ◽  
pp. 8588
Author(s):  
Xibin Ou ◽  
Xianyong Zhu ◽  
Peng Gu ◽  
Baichao Wang ◽  
Jing Li ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
High Efficiency ◽  
Circular Cross Section ◽  
Forming Process ◽  
Element Analysis ◽  
Spinning Process ◽  
Specific Geometry ◽  
Von Mises ◽  
Von Mises Stresses

This paper presents research on a new high-efficiency, non-circular spinning method based on hypocycloid theory. The trajectory of the roller during the forming process was derived, and the non-circular spinning process was simulated in ABAQUS 2016/Explicit. The distribution of von Mises stresses and equivalent plastic strains after each spinning pass were analyzed. The spinning quality was also investigated. This research proves the feasibility of spinning the workpieces of a non-circular cross-section using hypocycloid theory. This new non-circular spinning method can be used in practice to produce workpieces with a specific geometry and to increase the rotational speed of the workpiece from 60–240 rpm to 600 rpm, thereby improving the efficiency by around 2.5 times while maintaining acceptable forming quality.

Finite Element Analysis on the Blast Resistant Performance of Multibarrel Tube-Confined Concrete Column in Different Cross-Sections

2013 ◽  
Vol 721 ◽  
pp. 545-550
Author(s):  
Sai Wu ◽  
Jun Hai Zhao ◽  
Er Gang Xiong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Detonation Wave ◽  
Cross Section ◽  
Cross Sections ◽  
Failure Modes ◽  
Circular Cross Section ◽  
Blast Load ◽  
Element Analysis ◽  
The Impact

Based on the finite element analysis software ANSYS/LS-DYNA, this paper numerically analyzed the dynamic performance of MTCCCs with different cross sections under blast load, followed by the study and comparison on the differences of the detonation wave propagation and failure modes between the columns in circular cross section and square cross section. The results show: The blast resistant performance of the circular component is more superior than the square component for its better aerodynamic shape that can greatly reduce the impact of the detonation wave on the column; The main difference of the failure modes between the circular and square cross-sectional components under blast load lies in the different failure mode of the outer steel tube. The simulation results in this paper can provide some references for the blast resisting design of MTCCCs.

scholarly journals Finite Element Analysis of Different Hip Implant Designs along with Femur under Static Loading Conditions

2019 ◽  
Author(s):  
K N Chethan ◽  
N Shyamasunder Bhat ◽  
M Zuber ◽  
B Satish Shenoy
Keyword(s):  
Hip Joint ◽  
Cross Sections ◽  
Von Mises Stress ◽  
Implant Design ◽  
Element Analysis ◽  
Early 19Th Century ◽  
Hip Implant ◽  
Design Life ◽  
Von Mises ◽  
Von Mises Stresses

Background: The hip joint is the largest joint after the knee, which gives stability to the whole human structure. The hip joint consists of a femoral head which articulates with the acetabulum. Due to age and wear between the joints, these joints need to be replaced with implants which can function just as a natural joint. Since the early 19th century, the hip joint arthroplasty has evolved, and many advances have been taken in the field which improved the whole procedure. Currently, there is a wide variety of implants available varying in the length of stem, shapes, and sizes.Material and Methods: Circular, oval, ellipse and trapezoidal-shaped stem designs are considered in the present study. The human femur is modeled using Mimics. CATIA V-6 is used to model the implant models. Static structural analysis is carried out using ANSYS R-19 to evaluate the best implant design.Results: All the four hip implants exhibited the von Mises stresses, lesser than its yielded strength. However, circular and trapezoidal-shaped stems have less von Mises stress compared to ellipse and oval.Conclusion: This study shows the behavior of different implant designs when their cross-sections are varied. Further, these implants can be considered for dynamic analysis considering different gait cycles. By optimizing the implant design, life expectancy of the implant can be improved, which will avoid the revision of the hip implant in active adult patients.

Experimental and Numerical Study of Performance Behavior of Triangular Seal Under High Hydraulic Pressure

2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Bruno R. Mose ◽  
Hyun-Seok Lim ◽  
Dong-Kil Shin
Keyword(s):  
Numerical Simulation ◽  
Cross Section ◽  
Numerical Study ◽  
Hydraulic Pressure ◽  
Element Analysis ◽  
Rocket Propulsion ◽  
Fringe Patterns ◽  
Von Mises ◽  
Von Mises Stresses ◽  
Performance Behavior

In this paper, a seal with triangular cross section was proposed and its performance behavior under compression and various hydraulic pressures was analyzed through experimental and numerical methods. The seal was designed to have a 90 deg corner located near the extrusion gap while hydraulic pressure was applied at an inclination. With this design, it was found that even at hydraulic pressures of up to 18 MPa, the seal offered good fluid tight sealing capabilities without indications of extrusion failures. Such high pressure offers new possibilities for successful application of the seal in aircraft and rocket propulsion equipment. Moreover, the resistance of the seal against leakages was assured because measured contact stresses were greater than applied pressures. A numerical simulation through finite element analysis (FEA) showed that tilting of the delta ring even at angles of ±5 deg did not have any effect on the Von Mises stresses. The FEA results also demonstrated that the deformations and fringe patterns of delta ring were similar to the experimental results.

scholarly journals Study on Crush Tube Geometric Cross sections and Topology for Axial Crashworthiness

2020 ◽  
Vol 70 (3) ◽  
pp. 249-259
Author(s):  
T.J. Reddy ◽  
V. Narayanamurthy ◽  
Y.V.D. Rao
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Circular Cross Section ◽  
Road Vehicles ◽  
Element Analysis ◽  
Impact Forces ◽  
Axial Crush ◽  
Section Shape ◽  
Energy Absorbing ◽  
Initial Peak

Crush tubes are used as crash impact energy absorbing structure (EAS) and are located in the frontal compartment of road vehicles. Ideal crashworthiness of an EAS mandates that the equivalent decelerations due to impact forces should to be ≤ 20g; and crush force and stroke efficiencies should tend to unity. It is understood from the literature that no single geometric cross-section shape exhibits a near-ideal crashworthiness; and most EAS members exhibit a high initial peak crush force which is detrimental to the occupant safety, and moderate stroke and crush force efficiencies leading to a compromise in the total energy absorbed. In this paper, finite element analysis (FEA) methodology is formulated and experimentally validated for axial crush of a crush tube of SS304 material with circular cross section.  Subsequently, plastic deformation phenomenon and folding patterns in relation to crush force behaviour of crush tubes with various basic cross-sections of polygonal geometric shapes from triangle to octagon and circle are extensively studied through FEA. Further, two new geometric cross-section profiles with combination of basic shapes are proposed to combine the merits of different basic shapes. The crashworthiness of all basic cross-sections including the two proposed cross-section profiles is assessed based on standard parameters. The proposed new geometries may form a basis for the development of new EAS configurations for enhanced crashworthiness.

Determination of collapse moment of different angled pipe bends with initial geometric imperfection subjected to in-plane bending moments

2021 ◽  
pp. 095440622199640
Author(s):  
Manish Kumar ◽  
Pronab Roy ◽  
Kallol Khan
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Circular Cross Section ◽  
Initial Imperfection ◽  
Bend Angle ◽  
Bending Moments ◽  
Element Analysis ◽  
Geometric Imperfection ◽  
Initial Geometric Imperfection

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.

Impact of mandibular prognathism on morphology and loadings in temporomandibular joints

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jingheng Shu ◽  
Quanyi Wang ◽  
Desmond Y.R. Chong ◽  
Zhan Liu
Keyword(s):  
Finite Element Analysis ◽  
Pearson Correlation ◽  
Morphological Parameters ◽  
Element Analysis ◽  
Mandibular Prognathism ◽  
Temporomandibular Joints ◽  
Pearson Correlation Analysis ◽  
Von Mises ◽  
Von Mises Stresses ◽  
Asymptomatic Subjects

AbstractLoadings in temporomandibular joints (TMJs) are essential factors in dysfunction of TMJs, and are barely noticed in treatment of maxillofacial deformity. The only approach, which can access stresses in TMJs, could expend day’s even weeks to complete. The objective of the study was to compare the differences of the morphological and biomechanical characteristics of TMJs between asymptomatic subjects and patients with mandibular prognathism, and to preliminarily analyze the connection between the two kinds of characteristics. Morphological measurements and finite element analysis (FEA) corresponding to the central occlusion were carried out on the models of 13 mandibular prognathism patients and 10 asymptomatic subjects. The results indicated that the joint spaces of the patients were significantly lower than those of the asymptomatic subjects, while the stresses of patients were significantly greater than those of asymptomatic subjects, especially the stresses on discs. The results of Pearson correlation analysis showed that weak or no correlations were found between the von Mises stresses and the joint spaces of asymptomatic subjects, while moderate, even high correlations were found in the patients. Thus, it was shown to be a feasible way to use morphological parameters to predict the internal loads of TMJs.

scholarly journals Asymptotic Behavior of Stable Structures Made of Beams

2021 ◽  
Author(s):  
Georges Griso ◽  
Larysa Khilkova ◽  
Julia Orlik ◽  
Olena Sivak
Keyword(s):  
Asymptotic Behavior ◽  
Cross Section ◽  
Cross Sections ◽  
Linear Elasticity ◽  
Circular Cross Section ◽  
Linear Elasticity Theory ◽  
Linear Elastic ◽  
The Cross ◽  
Small Rotation ◽  
Stable Structures

AbstractIn this paper, we study the asymptotic behavior of an $\varepsilon $ ε -periodic 3D stable structure made of beams of circular cross-section of radius $r$ r when the periodicity parameter $\varepsilon $ ε and the ratio ${r/\varepsilon }$ r / ε simultaneously tend to 0. The analysis is performed within the frame of linear elasticity theory and it is based on the known decomposition of the beam displacements into a beam centerline displacement, a small rotation of the cross-sections and a warping (the deformation of the cross-sections). This decomposition allows to obtain Korn type inequalities. We introduce two unfolding operators, one for the homogenization of the set of beam centerlines and another for the dimension reduction of the beams. The limit homogenized problem is still a linear elastic, second order PDE.

scholarly journals Effect of liquid cooling on PCR performance with the parametric study of cross-section shapes of microchannels

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yousef Alihosseini ◽  
Mohammad Reza Azaddel ◽  
Sahel Moslemi ◽  
Mehdi Mohammadi ◽  
Ali Pormohammad ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Heat Sink ◽  
Evaluation Criteria ◽  
Circular Cross Section ◽  
Microchannel Heat Sink ◽  
Liquid Cooling ◽  
Maximum Heat ◽  
Maximum Heat Transfer

AbstractIn recent years, PCR-based methods as a rapid and high accurate technique in the industry and medical fields have been expanded rapidly. Where we are faced with the COVID-19 pandemic, the necessity of a rapid diagnosis has felt more than ever. In the current interdisciplinary study, we have proposed, developed, and characterized a state-of-the-art liquid cooling design to accelerate the PCR procedure. A numerical simulation approach is utilized to evaluate 15 different cross-sections of the microchannel heat sink and select the best shape to achieve this goal. Also, crucial heat sink parameters are characterized, e.g., heat transfer coefficient, pressure drop, performance evaluation criteria, and fluid flow. The achieved result showed that the circular cross-section is the most efficient shape for the microchannel heat sink, which has a maximum heat transfer enhancement of 25% compared to the square shape at the Reynolds number of 1150. In the next phase of the study, the circular cross-section microchannel is located below the PCR device to evaluate the cooling rate of the PCR. Also, the results demonstrate that it takes 16.5 s to cool saliva samples in the PCR well, which saves up to 157.5 s for the whole amplification procedure compared to the conventional air fans. Another advantage of using the microchannel heat sink is that it takes up a little space compared to other common cooling methods.

Semi-Enclosed Cold Forging Process Analysis and Progressive Die Design of CPU Fin

2008 ◽  
Vol 575-578 ◽  
pp. 174-179
Author(s):  
Juan Hua Su ◽  
Feng Zhang Ren ◽  
Lei Wang
Keyword(s):  
Production Efficiency ◽  
High Efficiency ◽  
Process Analysis ◽  
Die Design ◽  
Cold Forging ◽  
Forming Process ◽  
Element Analysis ◽  
Whole Process ◽  
Progressive Dies ◽  
Transfer Unit

This paper analyzes the forming process methods of fin used in CPU chip to emit heat. The whole process is blanking, the first forging forming, the second forging (sizing), and trimming. The chamfer design of CPU fin blank is simulated by finite element analysis. The optimized chamfer 1.6 mm is available. Semi-enclosed cold forging of progressive dies is put forward. The newly designed transfer unit is applied, which unifies the merit of high efficiency of the progressive dies and the high material-using ratio of the project die. Quick disassembly structure is designed and pins are used as quick disassembly pins by means of ball bearing bushing. The unique processing of the shearing scrap structure is adopted when designing the inverted trimming dies. Compared with the traditional die, the mechanization and electrization are realized to increase the production efficiency and get highly precise CPU fin.

scholarly journals Validation of Welding Simulations Using Thermal Strains Measured with DIC

2011 ◽  
Vol 70 ◽  
pp. 129-134 ◽  
Author(s):  
Maarten De Strycker ◽  
Pascal Lava ◽  
Wim Van Paepegem ◽  
Luc Schueremans ◽  
Dimitri Debruyne
Keyword(s):  
Residual Stresses ◽  
Cross Section ◽  
Circular Cross Section ◽  
Welding Process ◽  
Weld Bead ◽  
Image Correlation ◽  
Steel Tubes ◽  
Element Analysis ◽  
Strain Evolution ◽  
The Cross

Residual stresses can affect the performance of steel tubes in many ways and as a result their magnitude and distribution is of particular interest to many applications. Residual stresses in cold-rolled steel tubes mainly originate from the rolling of a flat plate into a circular cross section (involving plastic deformations) and the weld bead that closes the cross section (involving non-uniform heating and cooling). Focus in this contribution is on the longitudinal weld bead that closes the cross section. To reveal the residual stresses in the tubes under consideration, a finite element analysis (FEA) of the welding step in the production process is made. The FEA of the welding process is validated with the temperature evolution of the thermal simulation and the strain evolution for the mechanical part of the analysis. Several methods for measuring the strain evolution are available and in this contribution it is investigated if the Digital Image Correlation (DIC) technique can record the strain evolution during welding. It is shown that the strain evolution obtained with DIC is in agreement with that found by electrical resistance strain gauges. The results of these experimental measuring methods are compared with numerical results from a FEA of the welding process.

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