The Design and Analysis of Universal Inertial Switch Based MEMS

2012 ◽  
Vol 157-158 ◽  
pp. 308-311
Author(s):  
Yong Ping Hao ◽  
Li Ya Bao ◽  
Shuang Xi Gu
Keyword(s):  
Response Time ◽  
High Speed ◽  
Maximum Stress ◽  
Von Mises Stress ◽  
Inertial Switch ◽  
Von Mises ◽  
Continuous Power ◽  
The Impact ◽  
Fast Acting ◽  
Speed Response

In this paper, a novel MEMS inertial switch is designed and characterized for the purpose of crash sensing for ammunition systems in which high-speed response is required for triggering the detonator. In order to keep the same sensitivity in different direction, the structure of an annular proof-mass suspended by four serpentine flexures is designed. The switch can be integrated with electronics, fast-acting，and lack of a requirement for continuous power, and can be used in a wide area. The motion of the inertial switch is analyzed by dynamic simulation under the 700g threshold acceleration in y direction, the simulation results show that the response time is 0.142ms and the contact time of the switch is about 5 , it illustrates that the response time is short enough and the impact time satisfy the ask. The von-mises stress of the structure is calculate, the maximum stress occurs in the serpentine flexures, the value is 60.61 MPa, much less than the yield strength of the silicon, the switch can be used time after time.

Investigation of Meniscus Effect on Microbond Test of Typha Fiber/Epoxy Matrix

2020 ◽  
Vol 402 ◽  
pp. 14-19
Author(s):  
Andri Afrizal ◽  
Ikramullah ◽  
Syarizal Fonna ◽  
Syifaul Huzni
Keyword(s):  
Epoxy Matrix ◽  
Maximum Stress ◽  
Interfacial Shear Strength ◽  
Von Mises Stress ◽  
Microbond Test ◽  
The Matrix ◽  
The Difference ◽  
Von Mises ◽  
The Impact ◽  
Fiber Radius

The microbond test was one of the methods to examine the interfacial shear strength (IFSS) value of fiber and polymer matrix. The meniscus angle that formed at both ends of the matrix is difficult to control while manufacturing the specimen for the microbond test. Therefore, the effect of meniscus angle must be evaluated. In this paper, we evaluated the impact of variations of the meniscus angle against the maximum von-mises stress and the IFSS value of the Typha fiber epoxy matrix by finite element method. The geometry of the microbond test specimen was modeled with 0.25 mm fiber radius, 2 mm fiber length, 1.75 mm embedded length of the matrix, and varied the meniscus angles with 22°, 30°, 45°, 60°, 75°, and 90°. The mesh type quad-dominated CAX4R is used on fiber and matrix, while quad COHAX4 is applied to the cohesive element between fiber and matrix. The constantly applied displacement was adjusted to the upper end of the fiber at 0.6 mm. The simulation results showed that the difference in maximum stress obtained in each model. Furthermore, that is not given much difference in IFSS value. It can be concluded that the meniscus angle affects the maximum von-mises stress but not too much-affected IFSS value of the fiber and epoxy matrix.

Strength and Fatigue Analyses on Rotor in High Speed MU Traction Motor under Different Operating States

2011 ◽  
Vol 314-316 ◽  
pp. 1713-1716
Author(s):  
You Ming Jiang ◽  
Yi Huang Zhang ◽  
Yun Feng He ◽  
Hui Yu Xiang ◽  
Jun Ci Cao
Keyword(s):  
High Speed ◽  
Power Transmission ◽  
Von Mises Stress ◽  
Constant Power ◽  
Traction Motor ◽  
Long Duration ◽  
Starting Process ◽  
Von Mises ◽  
Safety Operation ◽  
The Impact

Considering the impact and the vibration that add to its driving system when high-speed MU running in the complex conditions, the rotor mechanical strength problems of a traction motor in MU power transmission system are studied, in this paper. The motor operating parameters when MU operating under different states, such as the starting process, the increasing voltage constant power process, and the constant voltage constant power process, are taken as the constraint boundary conditions in different situations. Considering the asymmetry of axial constraint, the distributions of both the Von Mises stress and the contact stress in rotor under different working states are analyzed, and the strength situation of rotor is evaluated. Then, the fatigue strength of rotor in a long duration rated operating is studied, and the fatigue weak position in rotor is found. The obtained results could provide a theoretical basis for the safety operation of traction motor in high-speed MU.

Continuum damage mechanics-based analysis of creep–fatigue interaction behavior in a turbine rotor

2018 ◽  
Vol 28 (3) ◽  
pp. 455-477 ◽  
Author(s):  
WZ Wang ◽  
YZ Liu
Keyword(s):  
Damage Mechanics ◽  
Maximum Stress ◽  
Continuum Damage Mechanics ◽  
Turbine Rotor ◽  
Von Mises Stress ◽  
Temperature Phase ◽  
Continuum Damage ◽  
Interaction Behavior ◽  
Creep Fatigue ◽  
The Impact

The aim of this study is to analyze the creep–fatigue interaction behavior of a steam turbine rotor under idealized cyclic thermomechanical loading conditions. A Chaboche model-based material constitutive model is applied to simulate the multiaxial stress–strain behavior in the rotor. Influence of accumulated damage during the whole iterations on the creep–fatigue interaction behavior is described by continuum damage mechanics. Analysis of the temperature and stress variations during the startup phase reveals that the startup phase can be divided into a condensation phase, a high steam flux phase, and an elevated temperature phase and that thermal stress reaches its maximum value in the condensation phase. In addition, creep–fatigue interaction in the rotor leads to a gradual decrease in the maximum stress; furthermore, comparison of the von Mises stress displays that the impact of damage accumulation results in the shift of the location with the maximum stress. Investigation of creep–fatigue damage discloses that the total damage is concentrated on the steam inlet notch zone and the blade groove of the first and third stages.

SuperMeshing: A Deep Learning Method for Boosting Mesh Density in Numerical Computation Within 2D Domain

2021 ◽  
Author(s):  
Handing Xu ◽  
Zhenguo Nie ◽  
Qingfeng Xu ◽  
Xinjun Liu
Keyword(s):  
Numerical Computation ◽  
Spatial Resolution ◽  
Maximum Stress ◽  
Linear Mapping ◽  
Stress Fields ◽  
Von Mises Stress ◽  
Full Detail ◽  
Mesh Density ◽  
Novel Method ◽  
Von Mises

Abstract Due to the limit of mesh density, the improvement of the spatial resolution of numerical computation always leads to a decrease in computing efficiency. Aiming at this inability of numerical computation, we propose a novel method for boosting the mesh density in finite element method (FEM) within 2D domain. Based on the von Mises stress fields of 2D plane-strain problems computed by the FEM, this method utilizes a deep neural network named SuperMeshingNet to learn a non-linear mapping from low mesh-density to high mesh-density in stress fields, and realizes the improvement of numerical computation accuracy and efficiency simultaneously. We adopt residual dense blocks into our mesh-density boost model – SuperMeshingNet to extract abundant local features and enhance the prediction capacity. The results indicate that SuperMeshingNet is able to effectively increase the spatial resolution of the von Mises stress fields under the multiple scaling factors: 2X,4X,and8X. Compared with the targets, the relative error of SuperMeshingNet is 2.44%, which shows better performance than the interpolation methods. Besides, SuperMeshingNet reveals an astonishing strength in predicting the maximum stress value. We publicly share our work with full detail of implementation at https://github.com/zhenguonie/2021_SuperMeshing_2D_Plane_Strain.

scholarly journals Tympanic Membrane Collagen Expression by Dynamically Cultured Human Mesenchymal Stromal Cell/Star-Branched Poly(ε-Caprolactone) Nonwoven Constructs

2020 ◽  
Vol 10 (9) ◽  
pp. 3043
Author(s):  
Stefania Moscato ◽  
Antonella Rocca ◽  
Delfo D’Alessandro ◽  
Dario Puppi ◽  
Vera Gramigna ◽  
...  
Keyword(s):  
Tympanic Membrane ◽  
Maximum Stress ◽  
Element Model ◽  
Von Mises Stress ◽  
Type I ◽  
Collagen Types ◽  
Collagen Expression ◽  
Polymerase Chain ◽  
Von Mises ◽  
Membrane Collagen

The tympanic membrane (TM) primes the sound transmission mechanism due to special fibrous layers mainly of collagens II, III, and IV as a product of TM fibroblasts, while type I is less represented. In this study, human mesenchymal stromal cells (hMSCs) were cultured on star-branched poly(ε-caprolactone) (*PCL)-based nonwovens using a TM bioreactor and proper differentiating factors to induce the expression of the TM collagen types. The cell cultures were carried out for one week under static and dynamic conditions. Reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) were used to assess collagen expression. A Finite Element Model was applied to calculate the stress distribution on the scaffolds under dynamic culture. Nanohydroxyapatite (HA) was used as a filler to change density and tensile strength of *PCL scaffolds. In dynamically cultured *PCL constructs, fibroblast surface marker was overexpressed, and collagen type II was revealed via IHC. Collagen types I, III and IV were also detected. Von Mises stress maps showed that during the bioreactor motion, the maximum stress in *PCL was double that in HA/*PCL scaffolds. By using a *PCL nonwoven scaffold, with suitable physico-mechanical properties, an oscillatory culture, and proper differentiative factors, hMSCs were committed into fibroblast lineage-producing TM-like collagens.

The Adaptive Blade Design and Evaluation of Wind Turbine

2010 ◽  
Vol 97-101 ◽  
pp. 2318-2323
Author(s):  
Wang Yu Liu ◽  
Jia Xing Gong ◽  
Xi Feng Liu ◽  
Xin Zhang
Keyword(s):  
Wind Turbine ◽  
Medial Axis ◽  
Coupling Effect ◽  
Design Method ◽  
Von Mises Stress ◽  
Blade Design ◽  
Adaptive Performance ◽  
Laminar Shear Stress ◽  
Von Mises ◽  
The Impact

This article explored the design method of the wind turbine blade being of flapping-twist adaptive performance and how to evaluate its feasibility and reliability according to the comprehensive factors. The results indicate that both spar cap and skin with off-axis carbon fiber can achieve the efficient flapping-twist coupling effect. Through overall investigation, the results show that the maximum fiber strains of tensile and compressive go up with increase of the off-axis angle, and the peak inter-laminar shear stress increase more rapidly. While, all of these evaluating indicators should be kept in the reference range for used materials. Moreover, when the off-axis angle increases, the peak Von Mises stress declines. In addition, the impact of natural frequencies on the blade design is proved to be insignificant. Finally, utilizing the medial axis laminates in the blade decoupled area is helpful to strengthen the blade fatigue resistivity.

Examination of the Stress Distribution in the Tip of a Pencil

2005 ◽  
Vol 73 (2) ◽  
pp. 335-337
Author(s):  
E. Pogozelski ◽  
D. Cole ◽  
M. Wesley
Keyword(s):  
Stress Distribution ◽  
Fracture Surface ◽  
Initial Position ◽  
Von Mises Stress ◽  
Shear Stresses ◽  
Worst Case ◽  
Position And Orientation ◽  
Von Mises ◽  
The Impact ◽  
Normal And Shear Stresses

The stresses within the tip of a pencil are examined theoretically, numerically, and experimentally to determine the position and orientation of the fracture surface. The von Mises stress is used to evaluate the impact of the normal and shear stresses due to compression, bending, torsion, and shear. The worst-case stress is shown to occur along the top edge of the inclined pencil point, where the normal stress is compressive. The resulting crack propagates diagonally downwards and towards the tip from this initial position, and is frequently observed to contain a cusp.

scholarly journals Pengembangan Alat Bantu Arbor untuk Pembuatan Roda Gigi pada Mesin Frais Vertikal

2021 ◽  
Vol 12 (2) ◽  
pp. 287-296
Author(s):  
Widodo Widodo ◽  
◽  
Rahman Hakim
Keyword(s):  
Metal Cutting ◽  
Engine Speed ◽  
Maximum Stress ◽  
Design Method ◽  
Machining Process ◽  
Von Mises Stress ◽  
Von Mises ◽  
Cutting Processes ◽  
Stress Simulation

The machining process is included in the classification of metal cutting processes, which are used to change the shape of metal or non-metallic product by cutting, peeling or separating. One of the machines used in this cutting process is a vertical type milling machine. This machine functions to make a product, one of which was a gear. The supporting equipment needed to make this gear was a vertical arbor tool. The material used in the manufacture of this product was a cast carbon steel type using the design method for manufacturing and assembly (DFMA), which began by examining and identifying needs, conceptualizing and designing products and making these products tailored to the dimensional specifications of standard and common cutter modules in the market. The results of the manufacture of this tool were directly tested for the manufacture of gears of various sizes and produced products whose deviations were within the tolerance of the measuring instrument, namely in the range 0 to 2%. In addition, the von Mises stress simulation at an engine speed of 150 Rpm, 450 Rpm and 750 Rpm and the resulting maximum stress was still below the yield limit, so it was safe to use.

scholarly journals Evaluation of Stress Distribution and Force in External Hexagonal Implant: A 3-D Finite Element Analysis

2021 ◽  
Vol 18 (19) ◽  
pp. 10266
Author(s):  
Vinod Bandela ◽  
Ram Basany ◽  
Anil Kumar Nagarajappa ◽  
Sakeenabi Basha ◽  
Saraswathi Kanaparthi ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Maximum Stress ◽  
Axial Direction ◽  
Von Mises Stress ◽  
P Value ◽  
Implant Surface ◽  
Element Analysis ◽  
Von Mises

Purpose: To analyze the stress distribution and the direction of force in external hexagonal implant with crown in three different angulations. Materials and Methods: A total of 60 samples of geometric models were used to analyze von Mises stress and direction of force with 0-, 5-, and 10-degree lingual tilt. Von Mises stress and force distribution were evaluated at nodes of hard bone, and finite element analysis was performed using ANSYS 12.1 software. For calculating stress distribution and force, we categorized and labeled the groups as Implant A1, Implant A2, and Implant A3, and Implant B1, Implant B2, and Implant B3 with 0-, 5-, and 10-degree lingual inclinations, respectively. Inter- and intra-group comparisons were performed using ANOVA test. A p-value of ≤0.05 was considered statistically significant. Results: In all the three models, overall maximum stress was found in implant model A3 on the implant surface (86.61), and minimum was found on model A1 in hard bone (26.21). In all the three models, the direction of force along three planes was maximum in DX (0.01025) and minimum along DZ (0.002) direction with model B1. Conclusion: Maximum von Mises stress and the direction of force in axial direction was found at the maximum with the implant of 10 degrees angulation. Thus, it was evident that tilting of an implant influences the stress concentration and force in external hex implants.

scholarly journals A Comparative Biomechanical Analysis of Various Rod Configurations Following Anterior Column Realignment and Pedicle Subtraction Osteotomy

Neurospine ◽  
2021 ◽  
Vol 18 (3) ◽  
pp. 587-596
Author(s):  
Muzammil Mumtaz ◽  
Justin Mendoza ◽  
Ardalan Seyed Vosoughi ◽  
Anthony S. Unger ◽  
Vijay K. Goel
Keyword(s):  
Stress Reduction ◽  
Factor Of Safety ◽  
Maximum Stress ◽  
Element Model ◽  
Pedicle Subtraction Osteotomy ◽  
Biomechanical Analysis ◽  
Anterior Column ◽  
Von Mises Stress ◽  
Correction Technique ◽  
Von Mises

Objective: The objective of this study was to compare the biomechanical differences of different rod configurations following anterior column realignment (ACR) and pedicle subtraction osteotomy (PSO) for an optimal correction technique and rod configuration that would minimize the risk of rod failure.Methods: A validated spinopelvic (L1-pelvis) finite element model was used to simulate ACR at the L3–4 level. The ACR procedure was followed by dual-rod fixation, and for 4-rod constructs, either medial/lateral accessory rods (connected to primary rods) or satellite rods (directly connected to ACR level screws). The range of motion (ROM), maximum von Mises stress on the rods, and factor of safety (FOS) were calculated for the ACR models and compared to the existing literature of different PSO rod configurations.Results: All of the 4-rod ACR constructs showed a reduction in ROM and maximum von Mises stress compared to the dual-rod ACR construct. Additionally, all of the 4-rod ACR constructs showed greater percentage reduction in ROM and maximum von Mises stress compared to the PSO 4-rod configurations. The ACR satellite rod construct had the maximum stress reduction i.e., 47.3% compared to dual-rod construct and showed the highest FOS (4.76). These findings are consistent with existing literature that supports the use of satellite rods to reduce the occurrence of rod fracture.Conclusion: Our findings suggest that the ACR satellite rod construct may be the most beneficial in reducing the risk of rod failure compared to all other PSO and ACR constructs.

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