scholarly journals Vibration Characteristic of the Bolter Arm under Heavy Load

2018 ◽  
Keyword(s):  
Vibration Characteristic ◽  
Heavy Load

scholarly journals Development of the Flexible Ring on an Elastic Continuous Foundation Tire Model for Planar Vibration of the Heavy Load Radial Tire

2018 ◽  
Vol 8 (11) ◽  
pp. 2064
Author(s):  
Zhihao Liu ◽  
Qinhe Gao ◽  
Hailong Niu
Keyword(s):  
Structural Parameters ◽  
Kinematic Characteristic ◽  
Vibration Characteristic ◽  
Tire Model ◽  
Inflation Pressure ◽  
Heavy Load ◽  
Coupling Vibration ◽  
Radial Tire ◽  
Planar Vibration ◽  
Flexible Ring

This paper investigates the planar vibration characteristic of heavy load radial tires with a large flat ratio. A proposed tire model with a flexible ring on an elastic continuous foundation is investigated utilizing kinematic modeling and experimental modal analysis. Planar coupling deformation of the radial and tangential direction is considered to enrich the kinematic characteristic of the flexible belt and the continuous sidewall; a flexible ring on an elastic continuous foundation tire model is proposed to investigate the coupling vibration characteristic between the flexible belt and the continuous sidewall. In-extensibility assumption is utilized to simplify the proposed tire model and the planar vibration modal features of the heavy load radial tire are discussed. The variation of the inflation pressure on the radial and tangential stiffness of the sidewall spring model is enriched into the flexible ring on an elastic continuous foundation tire model to extend the modal prediction of the tires with a different inflation pressure. Taking the relative error between the experimental and analytical modal resonance frequency of the tested tire with a different inflation pressure as the object value, structural parameters of the proposed tire model are identified by a backward genetic algorithm. Experimental and theoretical results show that: the planar coupling vibration characteristic of the heavy load radial tire can be predicted precisely with the flexible ring on an elastic continuous foundation tire model; meanwhile, considering the linear variations of the radial and tangential sidewall stiffness due to the inflation pressure, the proposed tire model can be extended to analyze the vibration characteristic of the heavy load radial tire with a different inflation pressure.

Organization Method of Asymmetric Two-Leg Displaced Left-Turn at Urban Intersection with Heavy Load

CICTP 2020 ◽  
2020 ◽  
Author(s):  
Gang Ren ◽  
Jingfeng Ma ◽  
Shunchao Wang ◽  
Jingcai Yu
Keyword(s):  
Heavy Load ◽  
Left Turn

scholarly journals Influence of finite element mesh size on the carrying capacity analysis of single-row ball slewing bearing

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110090
Author(s):  
Peiyu He ◽  
Qinrong Qian ◽  
Yun Wang ◽  
Hong Liu ◽  
Erkuo Guo ◽  
...  
Keyword(s):  
Finite Element ◽  
Carrying Capacity ◽  
Mesh Size ◽  
Finite Element Mesh ◽  
Fe Model ◽  
Element Mesh ◽  
Heavy Load ◽  
Slewing Bearing ◽  
Maximum Contact ◽  
Slewing Bearings

Slewing bearings are widely used in industry to provide rotary support and carry heavy load. The load-carrying capacity is one of the most important features of a slewing bearing, and needs to be calculated cautiously. This paper investigates the effect of mesh size on the finite element (FE) analysis of the carrying capacity of slewing bearings. A local finite element contact model of the slewing bearing is firstly established, and verified using Hertz contact theory. The optimal mesh size of finite element model under specified loads is determined by analyzing the maximum contact stress and the contact area. The overall FE model of the slewing bearing is established and strain tests were performed to verify the FE results. The effect of mesh size on the carrying capacity of the slewing bearing is investigated by analyzing the maximum contact load, deformation, and load distribution. This study of finite element mesh size verification provides an important guidance for the accuracy and efficiency of carrying capacity of slewing bearings.

scholarly journals Investigation of the Wear Behavior of PVD Coated Carbide Tools during Ti6Al4V Machining with Intensive Built Up Edge Formation

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 266
Author(s):  
M.S.I. Chowdhury ◽  
B. Bose ◽  
S. Rawal ◽  
G.S. Fox-Rabinovich ◽  
S.C. Veldhuis
Keyword(s):  
Tool Wear ◽  
Titanium Alloys ◽  
Wear Behavior ◽  
Cutting Temperature ◽  
Ti6al4v Alloy ◽  
Adhesive Interaction ◽  
Heavy Load ◽  
Micromechanical Properties ◽  
Rough Turning ◽  
Coated Carbide

Tool wear phenomena during the machining of titanium alloys are very complex. Severe adhesive interaction at the tool chip interface, especially at low cutting speeds, leads to intensive Built Up Edge (BUE) formation. Additionally, a high cutting temperature causes rapid wear in the carbide inserts due to the low thermal conductivity of titanium alloys. The current research studies the effect of AlTiN and CrN PVD coatings deposited on cutting tools during the rough turning of a Ti6Al4V alloy with severe BUE formation. Tool wear characteristics were evaluated in detail using a Scanning Electron Microscope (SEM) and volumetric wear measurements. Chip morphology analysis was conducted to assess the in situ tribological performance of the coatings. A high temperature–heavy load tribometer that mimics machining conditions was used to analyze the frictional behavior of the coatings. The micromechanical properties of the coatings were also investigated to gain a better understanding of the coating performance. It was demonstrated that the CrN coating possess unique micromechanical properties and tribological adaptive characteristics that minimize BUE formation and significantly improve tool performance during the machining of the Ti6Al4V alloy.

Examinations of a new long-term degradable electrospun polycaprolactone scaffold in three rat abdominal wall models

2017 ◽  
Vol 31 (7) ◽  
pp. 1077-1086 ◽  
Author(s):  
Hanna Jangö ◽  
Søren Gräs ◽  
Lise Christensen ◽  
Gunnar Lose
Keyword(s):  
Pelvic Organ Prolapse ◽  
Foreign Body ◽  
Abdominal Wall ◽  
Muscle Fiber ◽  
Pelvic Organ ◽  
Foreign Body Response ◽  
Heavy Load ◽  
Tissue Construct ◽  
Body Response

Alternative approaches to reinforce native tissue in reconstructive surgery for pelvic organ prolapse are warranted. Tissue engineering combines the use of a scaffold with the regenerative potential of stem cells and is a promising new concept in urogynecology. Our objective was to evaluate whether a newly developed long-term degradable polycaprolactone scaffold could provide biomechanical reinforcement and function as a scaffold for autologous muscle fiber fragments. We performed a study with three different rat abdominal wall models where the scaffold with or without muscle fiber fragments was placed (1) subcutaneously (minimal load), (2) in a partial defect (partial load), and (3) in a full-thickness defect (heavy load). After 8 weeks, no animals had developed hernia, and the scaffold provided biomechanical reinforcement, even in the models where it was subjected to heavy load. The scaffold was not yet degraded but showed increased thickness in all groups. Histologically, we found a massive foreign body response with numerous large giant cells intermingled with the fibers of the scaffold. Cells from added muscle fiber fragments could not be traced by PKH26 fluorescence or desmin staining. Taken together, the long-term degradable polycaprolactone scaffold provided biomechanical reinforcement by inducing a marked foreign-body response and attracting numerous inflammatory cells to form a strong neo-tissue construct. However, cells from the muscle fiber fragments did not survive in this milieu. Properties of the new neo-tissue construct must be evaluated at the time of full degradation of the scaffold before its possible clinical value in pelvic organ prolapse surgery can be evaluated.

scholarly journals Accuracy Improvement of Stator Inductance Identification Method Based on Low-Frequency Current Injection for Three-Level NPC Inverter-Fed IM Drives in Locked-Rotor Standstill Condition

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 488
Author(s):  
Yerganat Khojakhan ◽  
Kyoung-Min Choo ◽  
Junsin Yi ◽  
Chung-Yuen Won
Keyword(s):  
Induction Motor ◽  
Low Frequency ◽  
Current Injection ◽  
Heavy Load ◽  
Injection Test ◽  
Low Speed ◽  
Injection Speed ◽  
Speed Test ◽  
Identification Method ◽  
Drive Systems

In this paper, a stator inductance identification process is proposed. The process is based on a three-level neutral-point-clamped (NPC) inverter-fed induction motor (IM) drive with a standstill condition. Previously, a low-speed alternating current (AC) injection test for stator inductance identification was proposed to overcome practical problems in conventional identification methods for three-level NPC inverter-based IM drives. However, the low-speed AC injection test-based identification method has some problems if a heavy load or mechanical brake is connected, as these can forcibly bring the rotor to a standstill during parameter identification. Since this low-speed testing-based identification assumes the motor torque is considerably lower in low-speed operations, some inaccuracy is inevitable in this kind of standstill condition. In this paper, the proposed current injection speed generator is based on the previously studied low-speed test-based stator inductance identification method, but the proposed approach gives more accurate estimates under the aforementioned standstill conditions. The proposed method regulates the speed for sinusoidal low-frequency AC injection on the basis of the instantaneous reactive and air-gap active power ratio. This proposed stator inductance identification method is more accurate than conventional fixed low-frequency AC signal injection identification method for three-level NPC inverter-fed IM drive systems with a locked-rotor standstill condition. The proposed method’s accuracy and reliability were verified by simulation and experiment using an 18.5 kW induction motor.

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