Finite Element Simulation of Crack Compliance Experiments to Measure Residual Stresses in Thick-Walled Cylinders

2003 ◽  
Vol 125 (3) ◽  
pp. 305-308 ◽  
Author(s):  
R. R. de Swardt
Keyword(s):  
Finite Element ◽  
Hoop Stress ◽  
High Strength ◽  
Finite Element Models ◽  
Fe Model ◽  
Element Simulation ◽  
Highly Nonlinear ◽  
Strain Stress ◽  
Reverse Yielding ◽  
Stress States

A comparative study to map the residual strain/stress states through the walls of autofrettaged thick-walled high-strength steel cylinders has been conducted with neutron diffraction, Sachs boring, and the compliance methods. Test samples with different wall thickness ratios were prepared to have significant amounts of reverse yielding due to the Bauschinger effect. In an effort to explain observed differences in the hoop stress results, the crack compliance experiment was simulated with finite elements. Several residual stress fields were introduced in the finite element models. A theoretical finite element (FE) model, which is capable of accurately modeling the highly nonlinear reverse yielding of the material, was able to accurately predict the crack compliance strain measurements.

Strengthening Analysis on Tenon-Mortise Joint of a Face Beam in Tai-He Palace in the Forbidden City in China

2011 ◽  
Vol 255-260 ◽  
pp. 1597-1602
Author(s):  
Qian Zhou ◽  
Wei Ming Yan
Keyword(s):  
Finite Element ◽  
Composite System ◽  
Finite Element Models ◽  
Wood Composite ◽  
Stress Distributions ◽  
Element Simulation ◽  
The Face ◽  
As Stress ◽  
Strengthening Method ◽  
Cultural Relics

To protect Chinese ancient building,by theoretical calculation and finite element simulation sinkage as well as strengthening method on tenon-mortise joint of a face beam in Tai-He Palace in the Forbidden City were studied.2 strengthening methods were considered,by which calculation diagrams as well as finite element models for the beam were built and static analysis were carried out.Based on analysis results,displacement as well as stress distributions of the face beam before strengthened were obtained;Based on laws of cultural relics protection,the 2 strengthening methods were discussed and the more suitable one was selected.Results show that the main cause of sinkage of the face beam tenon relates closely to over great values of bending,tension as well as shearing stress values at the tenon-mortise joint position;The method that strengthening tenon-mortise joint by additional columns under the face beam may bring adverse effects to the substructure,however the method of using steel-wood composite system to strengthen the joint is more suitable which meets the demand of cultural relics protection.

Contrastive Study on Finite Element Models of High-Strength Pipelines Crossing Active Faults

2016 ◽  
Vol 850 ◽  
pp. 957-964
Author(s):  
Wei Zheng ◽  
Hong Zhang ◽  
Xiao Ben Liu ◽  
Le Cai Liang ◽  
Yin Shan Han
Keyword(s):  
Finite Element ◽  
Design Method ◽  
Active Faults ◽  
Shell Element ◽  
High Strength ◽  
Element Model ◽  
Beam Element ◽  
Finite Element Models ◽  
Fixed Boundary ◽  
Equivalent Boundary

There is a potential for major damage to the pipelines crossing faults, therefore the strain-based design method is essential for the design of buried pipelines. Finite element models based on soil springs which are able to accurately predict pipelines’ responses to such faulting are recommended by some international guidelines. In this paper, a comparative analysis was carried out among four widely used models (beam element model; shell element model with fixed boundary; shell element model with beam coupled; shell element model with equivalent boundary) in two aspects: differences of results and the efficiency of calculation. The results show that the maximum and minimum strains of models coincided with each other under allowable strain and the calculation efficiency of beam element model was the highest. Besides, the shell element model with beam coupled or equivalent boundary provided the reasonable results and the calculation efficiency of them were higher than the one with fixed boundary. In addition, shell element model with beam coupled had a broader applicability.

SEA model for structural acoustic coupling by means of periodic finite element models of the structural subsystems

2021 ◽  
Vol 263 (1) ◽  
pp. 5301-5309
Author(s):  
Luca Alimonti ◽  
Abderrazak Mejdi ◽  
Andrea Parrinello
Keyword(s):  
Finite Element ◽  
Numerical Approach ◽  
Unit Cell ◽  
Analytical Models ◽  
Finite Element Models ◽  
Fe Model ◽  
Acoustic Coupling ◽  
Representative Unit Cell ◽  
Definition Of ◽  
Acoustic Treatment

Statistical Energy Analysis (SEA) often relies on simplified analytical models to compute the parameters required to build the power balance equations of a coupled vibro-acoustic system. However, the vibro-acoustic of modern structural components, such as thick sandwich composites, ribbed panels, isogrids and metamaterials, is often too complex to be amenable to analytical developments without introducing further approximations. To overcome this limitation, a more general numerical approach is considered. It was shown in previous publications that, under the assumption that the structure is made of repetitions of a representative unit cell, a detailed Finite Element (FE) model of the unit cell can be used within a general and accurate numerical SEA framework. In this work, such framework is extended to account for structural-acoustic coupling. Resonant as well as non-resonant acoustic and structural paths are formulated. The effect of any acoustic treatment applied to coupling areas is considered by means of a Generalized Transfer Matrix (TM) approach. Moreover, the formulation employs a definition of pressure loads based on the wavenumber-frequency spectrum, hence allowing for general sources to be fully represented without simplifications. Validations cases are presented to show the effectiveness and generality of the approach.

Finite Element Simulation and Experimental Study on Blow Forming of Plastic Cups

2011 ◽  
Vol 148-149 ◽  
pp. 1319-1322
Author(s):  
Xiao Hu ◽  
Yi Sheng Zhang ◽  
Hong Qing Li ◽  
De Qun Li
Keyword(s):  
Finite Element ◽  
Thickness Distribution ◽  
Viscoelastic Model ◽  
Engineering Practice ◽  
Fe Model ◽  
Thin Wall ◽  
Forming Process ◽  
Element Simulation ◽  
Physically Based ◽  
Set Up

Blow forming process of plastic sheets is simple and easy to realize, thus, it is widely used for plastic thin-wall parts. In the practical production, an effective method is needed for the preliminary set-up of process parameters in order to achieve accurate control of thickness distribution. Thus, a finite element method (FEM) code is used to simulate blow forming process. For better description of complex material theological characteristics, a physically based viscoelastic model (VUMAT forms Buckley model) to model the complex constitutive behavior is used. Nonlinear FE analyses using ABAQUS were carried out to simulate the blow forming process of plastic cups. The actual values at different locations show a satisfactory agreement with the simulation results: as a matter of fact the error along the cell mid-section did not exceed 0.02 mm on average, corresponding to 5% of the initial thickness, thus the FE model this paper can meet the requirements of the engineering practice.

scholarly journals Finite Element Analysis of the Multilayered Honeycomb Composite Material Subjected to Impact Loading

2017 ◽  
Vol 54 (1) ◽  
pp. 180-179 ◽  
Author(s):  
Raul Cormos ◽  
Horia Petrescu ◽  
Anton Hadar ◽  
Gorge Mihail Adir ◽  
Horia Gheorghiu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Composite Material ◽  
Experimental Testing ◽  
Finite Element Models ◽  
The Finite Element Method ◽  
Low Velocity ◽  
Element Analysis ◽  
Element Simulation ◽  
Different Levels

The main purpose of this paper is the study the behavior of four multilayered composite material configurations subjected to different levels of low velocity impacts, in the linear elastc domain of the materials, using experimental testing and finite element simulation. The experimental results obtained after testing, are used to validate the finite element models of the four composite multilayered honeycomb structures, which makes possible the study, using only the finite element method, of these composite materials for a give application.

Research on Finite Element Method of Hot Forming of High Strength Steel Sheet

2021 ◽  
Vol 1032 ◽  
pp. 172-177
Author(s):  
Xiao Da Li ◽  
Xiang Hui Zhan
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
High Strength Steel ◽  
Strong Support ◽  
High Strength ◽  
Hot Forming ◽  
Mold Design ◽  
Deformation Method ◽  
Element Simulation ◽  
Simulation Based

The finite element simulation technology can provide strong support for the optimization of processing technology and the treatment of detailed problems in the processing process. Two finite element methods applied to hot forming of high-strength steel plates are introduced, namely the incremental method and the deformation method. Two methods are used for simulation calculations. The finite element simulation based on incremental theory has high accuracy and requires more complete mold and process information. It is mainly used in the middle and late stages of product and mold design. And the finite element simulation based on deformation theory have fast calculation speeds and are mainly used in the early stages of product and mold design. Both types of methods have high practical value.

Finite Element Simulation of Vacuum Hot Bulge Forming of Titanium Alloy Cylindrical Workpiece

2011 ◽  
Vol 675-677 ◽  
pp. 921-924 ◽  
Author(s):  
Ming Wei Wang ◽  
Chun Yan Wang ◽  
Li Wen Zhang
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Titanium Alloy ◽  
Finite Element Simulation ◽  
Process Parameters ◽  
Fe Model ◽  
Analysis Software ◽  
Forming Process ◽  
Element Simulation ◽  
Cylindrical Workpiece

Vacuum hot bulge forming (VHBF) is becoming an increasingly important manufacturing process for titanium alloy cylindrical workpiece in the aerospace industries. Finite element simulation is an essential tool for the specification of process parameters. In this paper, a two-dimensional nonlinear thermo-mechanical couple FE model was established. Numerical simulation of vacuum hot bulge forming of titanium alloy cylindrical workpiece was carried out using FE analysis software MSC.Marc. The effects of process parameter on vacuum hot bulge forming of BT20 titanium alloy cylindrical workpiece was analyzed by numerical simulation. The proposed an optimized vacuum hot bulge forming process parameters and die size. And the corresponding experiments were carried out. The simulated results agreed well with the experimental results.

Harmonic Wave Propagation of Ultrasonic Arc Stators

Aerospace ◽  
2003 ◽  
Author(s):  
P. Smithmaitrie ◽  
J. G. DeHaven ◽  
K. Higuchi ◽  
H. S. Tzou
Keyword(s):  
Finite Element ◽  
Traveling Waves ◽  
Traveling Wave ◽  
Harmonic Wave ◽  
Finite Element Models ◽  
Governing Equations ◽  
Modeling And Analysis ◽  
Element Simulation ◽  
Simulation Results ◽  
Harmonic Analyses

A piezoelectric curvilinear arc stator designed for an ultrasonic curvilinear motor is studied in this research. Design of piezoelectric curvilinear arc stator is proposed and its governing equations and vibration behavior are investigated. Then, analysis of forced vibration response or driving characteristics to harmonic excitations in the modal domain is conducted. Finite element modeling and analysis of the arc stator are also discussed. Analytical results of free vibration characteristics are compared favorably with the finite element results. Harmonic analyses of the three finite element models reveal changes of dynamic behaviors of three models and also imply operating frequencies with significant traveling wave component. Study of mathematical and finite element simulation results suggests that stable traveling waves can be generated to drive a motor on the proposed curvilinear arc stator system.

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