scholarly journals FE Analysis Of Meniscus Injury In A Square Stance Tennis Forehand Drive-a Case Study

2020 ◽  
Vol 52 (7S) ◽  
pp. 88-89
Author(s):  
Jingqiu Zhou ◽  
Hesheng Song ◽  
Jingguang Qian ◽  
Yu Liu ◽  
Hongwei Jiang ◽  
...  
Keyword(s):  
Fe Analysis ◽  
Meniscus Injury

scholarly journals Structural Redundancy Assessment of Adjacent Precast Concrete Box-Beam Bridges in Service

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yanling Leng ◽  
Jinquan Zhang ◽  
Ruinian Jiang ◽  
Yangjian Xiao
Keyword(s):  
Precast Concrete ◽  
Fe Analysis ◽  
Load Testing ◽  
Structural Redundancy ◽  
Simplified Approach ◽  
Box Beam ◽  
Nonlinear Fe Analysis ◽  
Redundancy Level ◽  
Real Behavior

Present approaches for assessing bridge redundancy are mainly based on nonlinear finite element (FE) analysis. Unfortunately, the real behavior of bridges in the nonlinear range is difficult to evaluate and a sound basis for the nonlinear FE analysis is not available. In addition, a nonlinear FE analysis is not feasible for practitioners to use. To tackle this problem, a new simplified approach based on linear FE analysis and field load testing is introduced in this paper to address the particular structural feature and topology of adjacent precast concrete box-beam bridges for the assessment of structural redundancy. The approach was first experimentally analyzed on a model bridge and then validated by a case study. The approach agrees well with the existing recognized method while reducing the computation complexity and improving the reliability. The analysis reveals that the level of redundancy of the bridge in the case study does not meet the recommended standard, indicating that the system factor recommended by the current bridge evaluation code for this bridge is inappropriate if considering the field condition. Further research on the redundancy level of this type of bridges is consequently recommended.

An Efficient Direct Calculation Approach for Fatigue Assessment of Container Ships Concerning Bending and Warping Stresses

2014 ◽  
Author(s):  
Zhiyuan Li ◽  
Wengang Mao ◽  
Jonas W. Ringsberg
Keyword(s):  
Beam Theory ◽  
Direct Calculation ◽  
Fe Analysis ◽  
Hydrodynamic Simulation ◽  
Fatigue Assessment ◽  
Hull Girder ◽  
Torsional Loads ◽  
Warping Stress

Container ships are particularly susceptible to torsional loads. The distribution of torsion-induced warping stress in a container ship hull is more complicated and difficult to be expressed by beam theory formulas. In practice, finite element (FE) analysis is typically used to calculate the stress response to wave-loading conditions. However, it is time consuming to compute hull girder stresses for all relevant sea conditions through FE analyses. In this paper, an efficient and robust approach is proposed by combining beam theory and FE analyses in the determination of hull girder stresses. The parameters required by beam theory can be regressed through matching stress records from a FE analysis with the corresponding sectional and pressure loads from the hydrodynamic simulation. Stress records obtained using the proposed method are utilized in fatigue assessment of a case study container vessel. The results show that the accuracy of the regression approach is satisfactory compared with the full FE analyses.

scholarly journals Slopes Analyses - Case Study, Slope Stability of Bypass Project

2021 ◽  
Vol 4 (2) ◽  
pp. 34
Author(s):  
Diana Bardhi
Keyword(s):  
Fe Analysis ◽  
Parameter Study ◽  
Dilatancy Angle ◽  
Pressure Distributions ◽  
Strain Relationship ◽  
Simple Slope ◽  
Coulomb Model ◽  
The Difference ◽  
The Stability

The scope of this study was to compare various stability evaluation methods. Accordingly, most common LE approaches were compared with the advanced LE (M‐P) method. Similarly, the differences in FOS computed from LE and FE analyses were compared based on a simple slope considering various load cases. In addition, two real slopes in a case study were analysed for the recorded minimum‐maximum GWT, pseudo‐static and dynamic conditions. Moreover, the stability evaluations of these slopes were based on both LE (M‐P) and FE (PLAXIS) calculation approaches, which both utilized shear strength parameters from advanced triaxle tests. Similarly, Mohr‐Coulomb model was applied in both approaches. The following conclusions are hence derived based on the reported work on both idealized and real slopes. To fulfil one of the aims of the study, the LE based methods are compared based on the factor of safety (FOS) obtained for various load combinations. The comparison is mainly based on simplified slope geometry and assumed input parameters. Among the LE methods, the Bishop simplified (BS), Janbu simplified (JS) and Janbu GPS methods are compared with the Morgenstern‐Price method (M‐PM). These LE methods are well established for many years, and thus some of them are still commonly used in practice for stability analysis. Moreover, the M‐PM has been compared with results from the FE analyses. Compared with theFE (PLAXIS) analyses, the LE (M‐PM) analyses may estimate 5 – 14percent higher FOS, depending on the conditions of a dry slope and a fully saturated slope with hydrostatic pore pressure distributions. For fully saturated conditions in the slope, inaccurate computation of stresses in LE methods may have resulted in larger difference in the computed FOS. Since, the FE software is based on stress‐strain relationship, stress redistributions are surely better computed even for a complicated problem. This has been found one of the advantages in FE simulations. A parameter study shows that the application of a positive dilatancy angle in FE analysis can significantly improve the FOS (4 ‐ 10percent). On contrast, the shear surface optimization in LE (M‐PM in SLOPE/W) analysis results in lower FOS, and thus minimizing the difference in FOS compared with FE analysis

scholarly journals Localization of Simulated Damage on a Steel Beam from Random Vibrations

2017 ◽  
Vol 62 (1) ◽  
pp. 112
Author(s):  
Jan Bayer ◽  
Jaromír Král ◽  
Shota Urushadze
Keyword(s):  
Limit State ◽  
Fe Analysis ◽  
New Combination ◽  
Mode Shapes ◽  
Steel Beam ◽  
Ultimate Limit State ◽  
Air Stream ◽  
Localization Criterion ◽  
Ultimate Limit

The performance of a few localization schemes using measured mode shapes was tested in an experimental case study with respect to the Ultimate Limit State (ULS). The first question to be posed was: Is it possible to indicate and locate damage under laboratory conditions before the ULS is reached? Relatively simple localization criteria were chosen, which do not require extensive FE analysis. A new combination of them, designated here as Combined Localization Criterion (CLI), was proposed that performed well in the presented case. A simple supported beam with the damage progressing in three consecutive stages was used for the experiments. Mode shapes in the range of up to 100 Hz were extracted from the response of the structure to the air stream.

Geosynthetic Reinforced Fill Material for Tennessee Bridge Approach Slab Support

2021 ◽  
pp. 036119812110286
Author(s):  
Wadi H. Imseeh ◽  
Khalid A. Alshibli ◽  
Murad Y. Abu-Farsakh ◽  
Ted A. Kniazewycz
Keyword(s):  
Sudden Change ◽  
Fe Analysis ◽  
Strip Footing ◽  
Smooth Transition ◽  
Potential Hazard ◽  
Department Of Transportation ◽  
Geogrid Reinforcement ◽  
Approach Slab ◽  
Bearing Stress

The approach slab is constructed at bridge ends to serve as a smooth transition from the highway pavement to the bridge deck. However, motorists usually complain about a sudden change in elevation (bump) at the highway/approach slab (H/S) joint that causes a potential hazard for public safety, damage to vehicles, and rider discomfort. This paper develops a finite element (FE) analysis for the differential settlement at the H/S joint when supported by a strip footing that sits on compacted layers of soil embankment with uniaxial geogrid reinforcement. A parametric study was conducted to select the optimum design that consists of five geogrid layers equally spaced within a depth of 2 [Formula: see text] below the strip footing, where [Formula: see text] is the width of the footing. The inclusion of geogrid reinforcement did not only enhance the ultimate bearing stress of the strip footing but also redistributed the vertical loads over a wider region of soil embankment and thus reduced settlement. A case study is also presented for modeling the performance of a preliminary design proposed by Tennessee Department of Transportation (TDOT) for the retrofit of bridge ends. The FE analysis showed a 30%–40% improvement in the ultimate bearing stress of the strip footing when the geogrid reinforcement proposed by TDOT is extended to a depth of 1.5 [Formula: see text] below the footing.

Deformation Analysis of Fixturing for Workpiece with Complex Geometry

2005 ◽  
Vol 291-292 ◽  
pp. 631-636 ◽  
Author(s):  
Yan Wang ◽  
Xun Chen ◽  
Nabil Gindy
Keyword(s):  
Finite Element ◽  
Turbine Blade ◽  
Complex Geometry ◽  
Early Stage ◽  
Fe Analysis ◽  
Accurate Prediction ◽  
Deformation Analysis ◽  
Design Problems ◽  
Surface Error

Finite element (FE) analysis is very useful in the early stage of a fixture development in order to reduce or eliminate design problems. Accurate prediction of fixture-workpiece deformation requires an appropriate representation of the contact relationship between fixture elements and workpieces. The paper addresses the special features of the deformation analysis between complicatedly shaped components and fixture elements. The effectiveness and the scope of applicability of commonly used methods are analysed. The verified FE analysis is used to predict surface error arising from deformations, and to evaluate the deformation distributions from fixture elements and workpiece. Based on the FE analysis, the tolerance can be allocated to the fixture elements and the workpiece. The development of a turbine blade fixture is provided as case study.

The Genesis and Internal Dynamics of El Salvador's People's Revolutionary Army, 1970–1976

2014 ◽  
Vol 38 (01) ◽  
pp. 102-129
Author(s):  
ALBERTO MARTÍN ÁLVAREZ ◽  
EUDALD CORTINA ORERO
Keyword(s):  
Latin America ◽  
El Salvador ◽  
Early Years ◽  
Left Wing ◽  
Internal Dynamics ◽  
Internal Coherence ◽  
The 1960S

AbstractUsing interviews with former militants and previously unpublished documents, this article traces the genesis and internal dynamics of the Ejército Revolucionario del Pueblo (People's Revolutionary Army, ERP) in El Salvador during the early years of its existence (1970–6). This period was marked by the inability of the ERP to maintain internal coherence or any consensus on revolutionary strategy, which led to a series of splits and internal fights over control of the organisation. The evidence marshalled in this case study sheds new light on the origins of the armed Salvadorean Left and thus contributes to a wider understanding of the processes of formation and internal dynamics of armed left-wing groups that emerged from the 1960s onwards in Latin America.

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