Blade Vibration Stress Determination Method Based on Blade Tip Timing Simulator and Finite Element Method

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Xiaojie Zhang ◽  
Yanrong Wang ◽  
Xianghua Jiang ◽  
Shimin Gao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Mode Shape ◽  
Fem Analysis ◽  
Axial Direction ◽  
Stress Determination ◽  
Modal Shape ◽  
Shape Information ◽  
Vibration Stress ◽  
Blade Tip

Abstract Blade tip timing (BTT) measurement technology is more widely used to determine the vibrational stress of rotating blades and play an important role for blade service life prediction. The dynamic blade displacements can be measured by tip timing sensors, and then be converted to blade stress by the modal shape information from finite element method (FEM) analysis. However, there are always two uncertainties between the measured displacements by BTT and the modal shape by FEM analysis. First, the effective positions detected by sensors may shift from where they expected due to the deformation of the blade. This deviation may yield calibration factors with deceptions, which will present an inaccurate correlation for the blade stress level and the tip displacement. Second, when vibrating, blade tip would actually oscillate around the equilibrium position both in circumferential and axial direction, while the sensors can only detect the movements along the circumference direction and neglect the other. This causes the measured displacements to be different from the actual displacements. To deal with these two problems, a novel method based on the vibration amplitudes of blade tip along axial direction is proposed to identify the effective detected position. The vibration stress of the whole blade then can be determined by linking the modified displacements to the mode shape information from finite element (FE) predictions. This method is validated by a numerical BTT simulator, which is trying to simulate the actual testing process of BTT measurement. Both synchronous and asynchronous vibrations are discussed to illustrate the applicability of this method. Moreover, sensitivity analysis is performed to identify the uncertainties from the vibration amplitude and mode shape inaccuracies. Results demonstrate the great potential of the method for vibration stress determination.

scholarly journals NURSE-2 DoF Device for Arm Motion Guidance: Kinematic, Dynamic, and FEM Analysis

2020 ◽  
Vol 10 (6) ◽  
pp. 2139
Author(s):  
Betsy D. M. Chaparro-Rico ◽  
Daniele Cafolla ◽  
Marco Ceccarelli ◽  
Eduardo Castillo-Castaneda
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Upper Limb ◽  
Numerical Procedure ◽  
Fem Analysis ◽  
Arm Movement ◽  
Assistive Device ◽  
Arm Motion ◽  
Element Method

Patients with neurological or orthopedic lesions require assistance during therapies with repetitive movements. NURSE (cassiNo-qUeretaro uppeR-limb aSsistive dEvice) is an arm movement aid device for both right- and left-upper limb. The device has a big workspace to conduct physical therapy or training on individuals including kids and elderly individuals, of any age and size. This paper describes the mechanism design of NURSE and presents a numerical procedure for testing the mechanism feasibility that includes a kinematic, dynamic, and FEM (Finite Element Method) analysis. The kinematic demonstrated that a big workspace is available in the device to reproduce therapeutic movements. The dynamic analysis shows that commercial motors for low power consumption can achieve the needed displacement, acceleration, speed, and torque. Finite Element Method showed that the mechanism can afford the upper limb weight with light-bars for a tiny design. This work has led to the construction of a NURSE prototype with a light structure of 2.6 kg fitting into a box of 35 × 45 × 30 cm. The latter facilitates portability as well as rehabilitation at home with a proper follow-up. The prototype presented a repeatability of ±1.3 cm that has been considered satisfactory for a device having components manufactured with 3D rapid prototyping technology.

FEM Analysis of Cylindrical Structural Elements under Local Shock Loading

2014 ◽  
Vol 566 ◽  
pp. 499-504 ◽  
Author(s):  
Leopold Kruszka ◽  
Yu.S. Vorobiov ◽  
N.Yu. Ovcharova
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
Shock Loading ◽  
Dynamic Properties ◽  
Fem Analysis ◽  
Finite Deformations ◽  
High Rate ◽  
Structural Elements ◽  
Stress Strain

High rate deformations of structures cylindrical elements are considered 3D formulation. Elastic-plastic finite deformations and dynamic properties of material take into account. The problem become geometrically and physically nonlinear and finite element method is used. The numerical analyses of dynamics stress-strain state of real structures elements is executed.

Curling Stress Equation for Transverse Joint Edge of a Concrete Pavement Slab Based on Finite-Element Method Analysis

1996 ◽  
Vol 1525 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Tatsuo Nishizawa ◽  
Tadashi Fukuda ◽  
Saburo Matsuno ◽  
Kenji Himeno
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fem Analysis ◽  
Concrete Pavement ◽  
Winkler Foundation ◽  
Stress Equation ◽  
The Past ◽  
Transverse Joint ◽  
Foundation Model ◽  
Element Method

In the design of concrete pavement, curling stresses caused by the temperature difference between the top and bottom surfaces of the slab should be calculated at the transverse joint edge in some cases. However, no such equation has been developed in the past. Accordingly, a curling stress equation was developed based on stress analysis using the finite-element method (FEM). In this FEM analysis, a concrete pavement and its transverse joint were expressed by means of a thin plate–Winkler foundation model and a spring joint model, respectively. Multiregression analysis was applied to the results of the FEM numerical calculation and, consequently, a curling stress equation was obtained. After comparing the calculated results of the equation with curling stress equations developed in the past, it was confirmed that the equation was valid and practical.

Prediction of mechanical behavior of 3D bioprinted tissue-engineered scaffolds using finite element method (FEM) analysis

2020 ◽  
Vol 33 ◽  
pp. 101181 ◽  
Author(s):  
Anahita Ahmadi Soufivand ◽  
Nabiollah Abolfathi ◽  
Seyyed Ataollah Hashemi ◽  
Sang Jin Lee
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Mechanical Behavior ◽  
Fem Analysis ◽  
Element Method

FEM Analysis on Thermal Stress of Desulphurization Injection Lance

2007 ◽  
Vol 336-338 ◽  
pp. 1531-1533
Author(s):  
Jian Qiang Qi ◽  
Yong Huang ◽  
Shi Xi Ouyang ◽  
Nan Li ◽  
Jiang Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Finite Element Method ◽  
Finite Element ◽  
Thermal Stress ◽  
Elastic Modulus ◽  
Fem Analysis ◽  
Finite Element Method Model ◽  
Method Model ◽  
Element Method

By means of a finite element method model, the effects of property parameters of refractory on thermal stress of injection lance have been studied. The results show that the maximum thermal stress increases with the improvement of thermal conductivity and elastic modulus of refractory, while it decreases at first and then increases with the improvement of the coefficient of expansion of refractory.

Analysis of Composite Shrinkage Stresses on 3D Premolar Models with Different Cavity Design Using Finite Element Method

2013 ◽  
Vol 586 ◽  
pp. 202-205 ◽  
Author(s):  
Milos Milosevic ◽  
Nenad Mitrovic ◽  
Vesna Miletić ◽  
Uroš Tatic ◽  
Andrea Ezdenci
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Models ◽  
Experimental Testing ◽  
Fem Analysis ◽  
Local Stress ◽  
Model Verification ◽  
Polymerization Shrinkage ◽  
Displacement Analysis ◽  
Element Method

Local polymerization stress occurs due to polymerization shrinkage of resin based composites adhesively bonded to tooth tissues. Shrinkage causes local displacements of cavity walls, with possible occurrence of micro-cracks in the enamel, dentin and/or material itself. In order to design a cavity for experimental testing of polymerization shrinkage of dental composites using 3D optical analysis, in this paper finite element method (FEM) was used to analyze numerical models with different cavity radiuses. 3D optical strain and displacement analysis of composite materials and cavity walls is limited by equipment sensitivity i.e. 0.01% for strain and 1 micron for displacement. This paper presents the development of 3D computer premolar models with varying cavity radiuses, and local stress, strain and displacement analysis using FEM. Model verification was performed by comparing obtained results with data from the scientific literature. Using the FEM analysis of local strains, displacements and stresses exerted on cavity walls, it was concluded that the model with 1 mm radius was optimal for experimental optical 3D displacement analysis.

A Puncturing Device that Mimics the Mechanism of Mosquito’s Proboscis and Labium - Verification of the Effect of Skin Deformation / Needle Buckling Prevention Mechanism and Puncture Experiment on Artificial Skin and Experimental Animals –

2020 ◽  
Vol 14 (1) ◽  
pp. 117-127
Author(s):  
Shunki Yamamoto ◽  
Seiji Aoyagi ◽  
Masahiro Yamada ◽  
Tomokazu Takahashi ◽  
Masato Suzuki ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Blood Flow ◽  
Fem Analysis ◽  
Artificial Skin ◽  
Resistance Force ◽  
Puncture Resistance ◽  
Experimental Animals ◽  
Skin Deformation ◽  
Laser Lithography

This paper proposes a mechanism for preventing needle buckling and skin deformation by mimicking the mosquito’s labium and discusses a puncturing device with a jig-integrated microneedle, based on the proposed mechanism. A sheet simplifying this mechanism was attached to an artificial skin’s surface, and experiments to puncture this artificial skin and corresponding finite element method (FEM) analysis were conducted. It was confirmed that the deformation of the puncture target and the puncture resistance force decreased with the use of the sheet. Based on these experimental and FEM-analytical results, a puncturing device with a jig-integrated needle has been designed and fabricated with 3D laser lithography. Experiments have been conducted with the fabricated device to puncture an artificial skin and the skin of a nude mouse to determine needle buckling prevention and the reduction in skin deformation. The study successfully samples blood from the mouse without stagnation of blood flow.

An Advanced Residual Stress Determination for 3D Cylinder Structure

2005 ◽  
Vol 490-491 ◽  
pp. 62-66 ◽  
Author(s):  
Jian Luo ◽  
Guillaume Montay ◽  
Jian Lu
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Hole Drilling ◽  
Stress Determination ◽  
Residual Stress Determination ◽  
Incremental Hole Drilling ◽  
Drilling Technique ◽  
The Relationship ◽  
Calibration Coefficients

For measuring in-depth residual stress in 3D cylinder structure easily in this paper, the semi-destructive incremental hole drilling technique combined with finite element method is used, the calibration coefficients of 3D cylinder components are calculated, and the relationship between strain and stress is determined, the changes of calibration coefficients are analysed, the residual stress of one steering joint of automobile is measured, and the errors of residual stress are discussed.

FEM Analysis for Seismic Performance of Large Aqueduct Structure with Different Bent-Height

2012 ◽  
Vol 170-173 ◽  
pp. 1837-1841
Author(s):  
Qiu Hua Duan ◽  
Lu Feng Yang ◽  
Meng Lin Lou
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Characteristic ◽  
Seismic Performance ◽  
Dynamic Stress ◽  
Water Pressure ◽  
Fem Analysis ◽  
Stress Reaction ◽  
Coupling Structure ◽  
Element Method

This paper mainly uses finite element method (FEM) to research how the bent-height influence on dynamic characteristic, acceleration reaction, dynamic water pressure, dynamic stress reaction of the aqueduct-water coupling structure seismic performance. Through calculation and analysis some significant results were obtained.

Sign in / Sign up

Export Citation Format

Share Document