Pole-Vaulting: Identification of the Pole Local Bending Rigidities by an Updating Technique

2008 ◽  
Vol 24 (2) ◽  
pp. 140-148 ◽  
Author(s):  
Julien Morlier ◽  
Michel Mesnard ◽  
Mariano Cid
Keyword(s):  
Finite Element ◽  
Composite Material ◽  
Performance Improvement ◽  
Mechanical Characteristics ◽  
Dynamic Structure ◽  
Experimental Results ◽  
The Other ◽  
Finite Element Models ◽  
Model Sensitivity ◽  
Deflection Test

The development of composite material poles since 1960 has played a prominent part in performance improvement in pole-vaulting. Previous studies devoted to pole-vaulting models were based on constant mechanical characteristics. It is thus necessary to identify the local bending rigidities of the pole to build realistic pole-vaulting models. Updating methods developed for dynamic structure studies allow us to describe local mechanical characteristics. These methods are based on the comparison between experimental results and those determined numerically by finite element models. This study presents an adaptation of these methods to determine the local bending rigidities of the pole. The updating technique is validated by a deflection test of a homogeneous beam. Then, a study of the model sensitivity is carried out to investigate the procedure robustness. Finally, the updating method is applied to an old design pole and to a recent one. The results obtained vary greatly from one pole to the other; they highlight the evolutions in pole design.

Comparison of flexural capacity of different hollow slab beams with/without pavement layer reinforced by steel plates

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Long Liu ◽  
Lifeng Wang ◽  
Ziwang Xiao
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Steel Plate ◽  
Plate Thickness ◽  
Experimental Results ◽  
Nonlinear Material ◽  
Finite Element Models ◽  
Rc Beams ◽  
Flexural Capacity ◽  
Content Type

PurposeReinforcement of reinforced concrete (RC) beams in-service have always been an important research field, anchoring steel plate in the bottom of the beams is a kind of common reinforcement methods. In actual engineering, the contribution of pavement layer to the bearing capacity of RC beams is often ignored, which underestimates the bearing capacity and stiffness of RC beams to a certain extent. The purpose of this paper is to study the effect of pavement layer on the RC beams before and after reinforcement.Design/methodology/approachFirst, static load experiments are carried out on three in-service RC hollow slab beams, meanwhile, nonlinear finite element models are built to study the bearing capacity of them. The nonlinear material and shear slip effect of studs are considered in the models. Second, the finite element models are verified, and the numerical simulation results are in good agreement with the experimental results. Last, the finite element models are adopted to carry out the research on the influence of different steel plate thicknesses on the flexural bearing capacity and ductility.FindingsThe experimental results showed that pavement layers increase the flexural capacity of hollow slab beams by 16.7%, and contribute to increasing stiffness. Ductility ratio of SPRCB3 and PRCB2 was 30% and 24% lower than that of RCB1, respectively. The results showed that when the steel plate thickness was 1 mm–6 mm, the bearing capacity of the hollow slab beam increased gradually from 2158.0 kN.m to 2656.6 kN.m. As the steel plate thickness continuously increased to 8 mm, the ultimate bearing capacity increased to 2681.0 kN.m. The increased thickness did not cause difference to the bearing capacity, because of concrete crushing at the upper edge.Originality/valueIn this paper, based on the experimental study, the bearing capacity of hollow beam strengthened by steel plate with different thickness is extrapolated by finite element simulation, and its influence on ductility is discussed. This method not only guarantees the accuracy of the bearing capacity evaluation, but also does not require a large number of samples, and has certain economy. The research results provide a basis for the reinforcement design of similar bridges.

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.

Isothermal Rolling of Mg-Based Laminated Composites Made by Explosion Cladding

2010 ◽  
Vol 443 ◽  
pp. 614-619 ◽  
Author(s):  
Xin Ping Zhang ◽  
Ming Jen Tan ◽  
Ting Hui Yang ◽  
Jing Tao Wang
Keyword(s):  
Finite Element ◽  
Composite Material ◽  
Elevated Temperature ◽  
Magnesium Alloy ◽  
Finite Element Methods ◽  
Strain Distribution ◽  
Experimental Results ◽  
Az31 Magnesium Alloy ◽  
Al Alloy ◽  
Layer Composite

Rolling of Al-Mg-Al tri-layer composite material fabricated by the explosion cladding method was simulated using finite element methods. The rolling temperature was determined based on the flow stresses of AZ31 magnesium alloy and 7075 Al alloy at elevated temperature. The strain distribution in the plates during rolling and effects of the reduction ratio on the separation in the Al/Mg/Al laminate were studied. The simulation agrees with experimental results.

Comparison of Feature Performance and its Application to Feature Combination in Off-Line Handwritten Korean Alphabet Recognition

1998 ◽  
Vol 12 (02) ◽  
pp. 251-261 ◽  
Author(s):  
Kukhwan Seo ◽  
Jongyeol Kim ◽  
Jongmin Yoon ◽  
Kyusik Chung
Keyword(s):  
Performance Improvement ◽  
Recognition Rate ◽  
Performance Comparison ◽  
Experimental Results ◽  
The Other ◽  
Feature Combination ◽  
Topological Features ◽  
Quantitative Performance ◽  
Combination Approach ◽  
Neural Network Classifiers

This paper presents (1) a quantitative performance comparison of the features used in off-line handwritten Korean alphabet recognition, and (2) some experimental results based on the feature combination approach. We classified the features into three: geometrical/topological, statistical and global. For each class, we selected four or five features and performed recognition experiments with PE92 database using neural network classifiers. We compared their recognition performances and selected the top four among those thirteen features: Up Down Left Right Hole, Gradient, Structure, and Mesh. With the combination of some or all of the four features, we repeated recognition experiments. Experimental results show that (1) as a whole, geometrical/topological features outperform the other two feature classes in terms of the recognition rate, and (2) UDLRH and Gradient features in geometrical/topological feature class outperform the other features, (3) the feature combination approach can result in performance improvement.

Finite Element Modeling in Musculoskeletal Biomechanics

2004 ◽  
Vol 20 (4) ◽  
pp. 336-366 ◽  
Author(s):  
Thomas D. Brown
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Numerical Approximation ◽  
The Other ◽  
Finite Element Models ◽  
Element Analysis ◽  
Femoral Head Osteonecrosis ◽  
Implant Dislocation ◽  
Technical Considerations

Numerical approximation of the solutions to continuum mechanics boundary value problems, by means of finite element analysis, has proven to be of incalculable benefit to the field of musculoskeletal biomechanics. This article briefly outlines the conceptual basis of finite element analysis and discusses a number of the key technical considerations involved, specifically from the standpoint of effective modeling of musculoskeletal structures. The process of conceiving, developing, validating, parametrically exercising, and interpreting the results of musculoskeletal finite element models is described. Pertinent case study examples are presented from two series of finite element models, one involving total hip implant dislocation and the other involving femoral head osteonecrosis.

Investigation of thermal properties of spacer fabrics with phase changing material by finite element model and experiment

2020 ◽  
Vol 90 (15-16) ◽  
pp. 1837-1850 ◽  
Author(s):  
Rimantas Barauskas ◽  
Audrone Sankauskaite ◽  
Vitalija Rubeziene ◽  
Ausra Gadeikyte ◽  
Virginija Skurkyte-Papieviene ◽  
...  
Keyword(s):  
Finite Element ◽  
Phase Change ◽  
Specific Heat ◽  
Finite Element Simulation ◽  
Phase Change Material ◽  
Phase Change Materials ◽  
Experimental Results ◽  
Finite Element Models ◽  
Element Simulation ◽  
Change Material

This study presents the developed computational finite element models for transient heat transfer analysis in fabrics enriched by phase change materials along with efforts to provide validation on the basis of obtained experimental results. The environment-friendly butyl stearate is used as a phase change material. Its melting/heating absorption takes place in temperature range from 19℃ to 34℃, and the solidification/heat release occurs from 34℃ to 19℃. An important aspect in this analysis is the investigation of appropriateness of the material samples dimensions selected for effective heat capacity against temperature measurements. For this purpose, we used the combined experimental and finite element simulation-based analysis. A similar computational procedure enabled us to estimate the effective latent specific heat relationship of the fabric with phase change materials coating. The direct usage of differential scanning calorimetry (DSC) measurement-based specific heat relationships against temperature in the finite element models ensured good compliance of the computed results with the experiment. For validation of the developed computational models the infrared radiation heating-cooling experiments on fabrics with different deposits of a phase change material were performed. The noticeable influence of content of phase change materials for transient thermal behavior during heating-cooling cycles was determined. The experimental results have been compared against the finite element simulation results.

scholarly journals Preliminary Finite Element Analysis of Locomotive Crashworthy Components

2011 ◽  
Author(s):  
Patricia Llana ◽  
Richard Stringfellow
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Energy Management ◽  
New Technologies ◽  
The Other ◽  
Finite Element Models ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Passenger Trains ◽  
Deformation Modes

The Office of Research and Development of the Federal Railroad Administration (FRA) and the Volpe Center are continuing to evaluate new technologies for increasing the safety of passengers and operators in rail equipment. In recognition of the importance of override prevention in train-to-train collisions in which one of the vehicles is a locomotive, and in light of the success of crash energy management technologies in cab car-led passenger trains, the Volpe Center seeks to evaluate the effectiveness of components that could be integrated into the end structure of a locomotive that are specifically designed to mitigate the effects of a collision and, in particular, to prevent override of one of the lead vehicles onto the other. A research program is being conducted that aims to develop, fabricate and test two crashworthy components for the forward end of a locomotive: (1) a deformable anti-climber, and (2) a push-back coupler. Preliminary designs for these components have been developed. This paper provides details on the finite element models of the crashworthy components and how the component designs behave in the finite element analyses. The component designs will be evaluated to determine if the requirements have been met, such as the energy absorption capability, deformation modes, and force/crush characteristics.

scholarly journals More Than Six Elements Per Wavelength: The Practical Use of Structural Finite Element Models and Their Accuracy in Comparison with Experimental Results

2017 ◽  
Vol 25 (04) ◽  
pp. 1750025 ◽  
Author(s):  
P. Langer ◽  
M. Maeder ◽  
C. Guist ◽  
M. Krause ◽  
S. Marburg
Keyword(s):  
Finite Element ◽  
High Precision ◽  
Analytical Solutions ◽  
Experimental Results ◽  
Finite Element Models ◽  
Benchmark Tests ◽  
Simulation And Experiment ◽  
Performance Check ◽  
The Right ◽  
Bending Wave

Choosing the right number and type of elements in modern commercial finite element tools is a challenging task. It requires a broad knowledge about the theory behind or much experience by the user. Benchmark tests are a common method to prove the element performance against analytical solutions. However, these tests often analyze the performance only for single elements. When investigating the complete mesh of an arbitrary structure, the comparison of the element’s performance is quite challenging due to the lack of closed or fully converged solutions. The purpose of this paper is to show a high-precision comparison of eigenfrequencies of a real structure between experimental and numerical results in the context of an element performance check with respect to a converged solution. Additionally, the authors identify the practically relevant accuracy of simulation and experiment. Finally, the influence of accuracy with respect to the number of elements per standing structural bending wave is shown.

Development of a customized density—modulus relationship for use in subject-specific finite element models of the ulna

2009 ◽  
Vol 223 (6) ◽  
pp. 787-794 ◽  
Author(s):  
R L Austman ◽  
J S Milner ◽  
D W Holdsworth ◽  
C E Dunning
Keyword(s):  
Finite Element ◽  
Cortical Bone ◽  
Material Properties ◽  
Beam Theory ◽  
Average Density ◽  
Experimental Results ◽  
Finite Element Models ◽  
Theory Analysis ◽  
Distal Ulna ◽  
Subject Specific

Assigning an appropriate density—modulus relationship is an important factor when applying inhomogeneous material properties to finite element models of bone. The purpose of this study was to develop a customized density—modulus equation for the distal ulna, using beam theory combined with experimental results. Five custom equations of the form E = aρb were used to apply material properties to models of eight ulnae. All equations passed through a point (1.85, Ec), where ρ = 1.85 g/cm3 represents the average density of cortical bone. For custom equations (1) to (3), Ec was predicted using beam theory, and the value of b was varied within the range reported in the literature. Custom equations (4) and (5) used other values of Ec from the literature, while keeping b constant. Results obtained from the custom equations were compared with those from other equations in the literature, and with experimental results. The beam theory analysis predicted Ec = 21 ± 1.6 GPa, and the three custom equations using this value tended to have the lowest errors. The power of the equations did not affect the results as much as the value used for Ec. Overall, a customized density—modulus relationship for the ulna was generated, which provided improved results over using previously reported density—modulus equations.

scholarly journals Textile wing fabric for emergency response UAS

2020 ◽  
Vol 71 (04) ◽  
pp. 321-326
Author(s):  
ADRIAN SĂLIȘTEAN ◽  
CARMEN MIHAI
Keyword(s):  
Emergency Response ◽  
Mechanical Characteristics ◽  
Statistical Data ◽  
Breaking Strength ◽  
Air Permeability ◽  
Experimental Results ◽  
The Other ◽  
Shape Stability ◽  
International Testing

The fabrics used to manufacture parachutes and paragliders must have several specific characteristics: the mass of fabric per unit of surface must be low while the other physical-mechanical characteristics (the axial breaking strength load, the relative and absolute elongation, the tear resistance of the fabric and the assemblies, air permeability) must have high values. The paper deals with the analysis of qualitative aspects of several parachute fabrics that are used as a baseline in the development of a novel fabric. The results of experiments have materialized in statistical data, diagrams and graphs and their interpretation leads to the determination of the fabric variant that best meets the requirements of the destination. The destination is a patent pending inflatable wing design that utilizes a single skin construction and solid reinforcements in the sewing for shape stability. It is worth noting that the experimental results were compared with values indicated in specific international testing norms.

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