scholarly journals A Finite Element Investigation into the Effect of Slope of Grain on Wood Baseball Bat Durability

2019 ◽  
Vol 9 (18) ◽  
pp. 3733 ◽  
Author(s):  
Joshua Fortin-Smith ◽  
James Sherwood ◽  
Patrick Drane ◽  
Eric Ruggiero ◽  
Blake Campshure ◽  
...  
Keyword(s):  
Finite Element ◽  
Wood Density ◽  
Wood Species ◽  
Parametric Study ◽  
Material Behavior ◽  
Finite Element Models ◽  
Ball Speed ◽  
Ball Impact ◽  
Fundamental Understanding ◽  
The Relationship

Bat durability is defined as the relative bat/ball speed that results in bat breakage, i.e., the higher the speed required to initiate bat cracking, the better the durability. In 2008, Major League Baseball added a regulation to the Wooden Baseball Bat Standards concerning Slope-of-Grain (SoG), defined to be the angle of the grain of the wood in the bat with respect to a line parallel to the longitudinal axis of the bat, as part of an overall strategy to reverse what was perceived to be an increasing rate of wood bats breaking into multiple pieces during games. The combination of a set of regulations concerning wood density, prescribed hitting surface, and SoG led to a 30% reduction in the rate of multi-piece failures. In an effort to develop a fundamental understanding of how changes in the SoG impact the resulting bat durability, a popular professional bat profile was examined using the finite element method in a parametric study to quantify the relationship between SoG and bat durability. The parametric study was completed for a span of combinations of wood SoGs, wood species (ash, maple, and yellow birch), inside-pitch and outside-pitch impact locations, and bat/ball impact speeds ranging from 90 to 180 mph (145 to 290 kph). The *MAT_WOOD (MAT_143) material model in LS-DYNA was used for implementing the wood material behavior in the finite element models. A strain-to-failure criterion was also used in the *MAT_ADD_EROSION option to capture the initiation point and subsequent crack propagation as the wood breaks. Differences among the durability responses of the three wood species are presented and discussed. Maple is concluded to be the most likely of the three wood species to result in a Multi-Piece Failure. The finite element models show that while a 0°-SoG bat is not necessarily the most durable configuration, it is the most versatile with respect to bat durability. This study is the first comprehensive numerical investigation as to the relationship between SoG and bat durability. Before this numerical study, only limited empirical data from bats broken during games were available to imply a qualitative relationship between SoG and bat durability. This novel study can serve as the basis for developing future parametric studies using finite element modeling to explore a large set of bat profiles and thereby to develop a deeper fundamental understanding of the relationship among bat profile, wood species, wood SoG, wood density, and on-field durability.

Axial strength of steel circular hollow section (CHS) X-joints strengthened by flanged larger pipe

2020 ◽  
Vol 47 (3) ◽  
pp. 301-316
Author(s):  
Peter Gerges ◽  
Sameh Gaawan ◽  
Ashraf Osman
Keyword(s):  
Finite Element ◽  
Parametric Study ◽  
Thickness Ratio ◽  
Finite Element Models ◽  
T Joints ◽  
Hollow Section ◽  
Axial Strength ◽  
Structural Joints ◽  
Circular Hollow Section ◽  
Steel Design

In steel design, enhancing the structural joints’ capacity is considered a challenge that faces the designer. This challenge becomes more difficult when it comes to enhancing the capacities of circular hollow section (CHS) joints due to their closed nature that complicates the strengthening process. Recent research related to strengthening T-joints by utilizing two outer hollow ring flanges welded to additional pipe showed that this technique can significantly improve the joints’ strength. In this study, the utilization of this technique is extended for enhancing the axial strength of CHS X-joints. In this regard, a parametric study using finite element models was carried out to investigate the different design aspects that might affect the behavior of strengthened X-joints. The examined parameters included, the ring flange diameter, the stiffening pipe thickness and length for different brace diameter-to-chord diameter ratios and chord diameter to double chord thickness ratio. The results demonstrated that these strengthened X-joints gained significant axial strength that reached up to three times the axial strength of the unstrengthened joints. Guidelines for proper detailing of such strengthening scheme were provided. Finally, an equation that estimates the axial strength of strengthened joints was established based on the achieved results.

Modal Velocity-Based Multiaxial Fatigue Damage Evaluation Using Simplified Finite Element Models

2020 ◽  
Vol 87 (11) ◽  
Author(s):  
Kurthan Kersch ◽  
Elmar Woschke
Keyword(s):  
Finite Element ◽  
Fatigue Damage ◽  
Cross Section ◽  
Multiaxial Fatigue ◽  
Finite Element Models ◽  
Damage Evaluation ◽  
Geometric Factors ◽  
The Relationship ◽  
General Method

Abstract This work proposes a new method for the fatigue damage evaluation of vibrational loads, based on preceding investigations on the relationship between stresses and modal velocities. As a first step, the influence of the geometry on the particular relationship is studied. Therefore, an analytic expression for Euler Bernoulli beams with a non-constant cross section is derived. Afterward, a general method for obtaining geometric factors from finite element (FE) models is proposed. In order to ensure a fast fatigue damage evaluation, strongly simplified FE-models are used for the determination of both factors and measurement locations. The entire method is demonstrated on three mechanical structures and indicates a better compromise between effort and accuracy than existing methods. For all examples, the usage of velocities and geometric factors obtained from simplified FE models enables a sufficient fatigue damage calculation.

The Collagen Fiber Kinematics in the Anteroinferior Glenohumeral Capsule Are Not Affine-Predicted

2011 ◽  
Author(s):  
Carrie A. Voycheck ◽  
Patrick J. McMahon ◽  
Richard E. Debski
Keyword(s):  
Finite Element ◽  
Structural Model ◽  
Glenohumeral Joint ◽  
Structural Models ◽  
Clinical Problem ◽  
Collagen Fibers ◽  
Material Behavior ◽  
Finite Element Models ◽  
Glenohumeral Ligament ◽  
Glenohumeral Capsule

Glenohumeral dislocation is a significant clinical problem and often results in injury to the anteroinferior (anterior band of the inferior glenohumeral ligament (AB-IGHL) and axillary pouch) glenohumeral capsule. [1] However, clinical exams to diagnose capsular injuries are not reliable [2] and poor patient outcome still exists following repair procedures. [3] Validated finite element models of the glenohumeral capsule may be able to improve diagnostic and repair techniques; however, improving the accuracy of these models requires adequate constitutive models to describe capsule behavior. The collagen fibers in the anteroinferior capsule are randomly oriented [4], thus the material behavior of the glenohumeral capsule has been described using isotropic models. [5,6] A structural model consisting of an isotropic matrix embedded with randomly aligned collagen fibers proved to better predict the complex capsule behavior than an isotropic phenomenological model [7] indicating that structural models may improve the accuracy of finite element models of the glenohumeral joint. Many structural models make the affine assumption (local fiber kinematics follow global tissue deformation) however an approach to account for non-affine fiber kinematics in structural models has been recently developed [8]. Evaluating the affine assumption for the capsule would aid in developing an adequate constitutive model. Therefore, the objective of this work was to assess the affine assumption of fiber kinematics in the anteroinferior glenohumeral capsule by comparing experimentally measured preferred fiber directions to the affine-predicted fiber directions.

Euler Buckling of Idealised Horizontal Pipeline Imperfections

2010 ◽  
Author(s):  
Gary Cumming ◽  
Andrew Rathbone
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Friction Factor ◽  
Finite Element Models ◽  
Bend Radius ◽  
Element Analysis ◽  
Euler Buckling ◽  
Critical Buckling Force ◽  
The Relationship

Imperfections introduced by pipelay can not be known until installation is complete; therefore a common approach is to perform finite element analysis of idealised horizontal imperfections to determine critical buckling forces. Rundsag et al 2008 [1], showed that the critical buckling force for a snake lay geometry is directly proportional to the pipeline bend radius. Rathbone et al 2008 [2] showed that, with decreasing arch lengths, the pipeline critical buckling force is proportional to the change in the offset angle. This paper looks at the relationship between the minimum critical buckling force and the horizontal offset angle of the pipeline, considering an Euler buckling approach. The resulting relationship that estimates the critical buckle load based on pipeline stiffness and weight, offset angle and friction factor is then compared against idealised finite element models.

Multiphase Poroelastic Finite Element Models for Soft Tissue Structures

1992 ◽  
Vol 45 (6) ◽  
pp. 191-218 ◽  
Author(s):  
Bruce R. Simon
Keyword(s):  
Finite Element ◽  
Soft Tissue ◽  
Material Behavior ◽  
Constitutive Law ◽  
Finite Strains ◽  
Finite Element Models ◽  
Tissue Fluid ◽  
Biomechanical Models ◽  
Highly Nonlinear ◽  
Tissue Structures

During the last two decades, biological structures with soft tissue components have been modeled using poroelastic or mixture-based constitutive laws, i.e., the material is viewed as a deformable (porous) solid matrix that is saturated by mobile tissue fluid. These structures exhibit a highly nonlinear, history-dependent material behavior; undergo finite strains; and may swell or shrink when tissue ionic concentrations are altered. Given the geometric and material complexity of soft tissue structures and that they are subjected to complicated initial and boundary conditions, finite element models (FEMs) have been very useful for quantitative structural analyses. This paper surveys recent applications of poroelastic and mixture-based theories and the associated FEMs for the study of the biomechanics of soft tissues, and indicates future directions for research in this area. Equivalent finite-strain poroelastic and mixture continuum biomechanical models are presented. Special attention is given to the identification of material properties using a porohyperelastic constitutive law and a total Lagrangian view for the formulation. The associated FEMs are then formulated to include this porohyperelastic material response and finite strains. Extensions of the theory are suggested in order to include inherent viscoelasticity, transport phenomena, and swelling in soft tissue structures. A number of biomechanical research areas are identified, and possible applications of the porohyperelastic and mixture-based FEMs are suggested.

Performance of Embedded Mooring Lines During Keying and Diving of Gravity Installed Anchors

2018 ◽  
Author(s):  
Yanbing Zhao ◽  
Haixiao Liu
Keyword(s):  
Finite Element ◽  
Drag Force ◽  
Parametric Study ◽  
Oil And Gas ◽  
Strain Softening ◽  
Three Dimensional ◽  
Frictional Coefficient ◽  
Mooring Lines ◽  
Soil Strain ◽  
The Relationship

Gravity installed anchors (GIAs) are the most recent generation of anchoring solution to moor floating facilities for deepwater oil and gas developments. After the installation of GIAs, the anchors are connected with the floating facility via the mooring lines, which interact with the anchors at the shackle and influence the keying and diving performance of GIAs. In the present work, a three-dimensional large deformation finite element (LDFE) model is established using the coupled Eulerian–Lagrangian method to investigate the performance of embedded mooring lines during keying and diving of GIAs. To verify the efficiency of the LDFE model, comparisons with the plasticity models are performed. Then, a parametric study is undertaken to quantify the relationship between the drag force Ta and drag angle θah at the shackle and the drag force T0 and drag angle θ0 at the mudline, in terms of the frictional coefficient, drag angle at the mudline and soil strain rate and strain softening. It is demonstrated that the drag angle at the mudline has the most significant effect on the performance of embedded mooring lines and hence the keying and diving of GIAs.

Characterizing Guardrail Steel for LS-DYNA3D Simulations

1996 ◽  
Vol 1528 (1) ◽  
pp. 138-145 ◽  
Author(s):  
Amy E. Wright ◽  
Malcolm H. Ray
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Material Behavior ◽  
Finite Element Models ◽  
Type Ii ◽  
Material Models ◽  
Class A ◽  
Model Geometry ◽  
Simulation Results ◽  
Roadside Hardware

Finite-element models have three parts: geometry, connections, and material properties. As the visible parts of a model, geometry and connections are generally carefully considered. Material properties often are not chosen with the same degree of care although they are equally important to obtaining good results. Accurate simulations of vehicles striking roadside hardware require an understanding of both the material behavior and the mathematical material models in LS-DYNA3D. A method for comparing LS-DYNA3D simulations with typical ASTM materials tests is described. The behavior and modeling parameters of guardrail steel (AASHTO M-180 Class A Type II) are examined in this study. Experimental and simulation results of quasistatic coupon tests are compared for AASHTO M-180 Class A Type II guardrail steel, and parameters for guardrail steel are recommended.

Parametric study of a VLSI plastic package using locally refined finite element models

1989 ◽  
Author(s):  
B.R. Simon ◽  
Y. Yuan ◽  
J.R. Umaretiya ◽  
J.L. Prince ◽  
Z.J. Staszak
Keyword(s):  
Finite Element ◽  
Parametric Study ◽  
Finite Element Models ◽  
Plastic Package

Ultimate Strength of Box Girders With Incline Cracks

2015 ◽  
Author(s):  
Lei Ao ◽  
Deyu Wang
Keyword(s):  
Finite Element ◽  
Fourier Series ◽  
Crack Length ◽  
Ultimate Strength ◽  
Finite Element Models ◽  
Torsional Loading ◽  
Box Girders ◽  
Box Beam ◽  
Crack Angle ◽  
The Relationship

The aim of the present study is to investigate the residual ultimate strength characteristics of box girders with variable inclination cracks under torsional loading. A series of finite element models are established by changing the crack length and crack angle using a commercial FEA program, ABAQUS. The cracks are located at the center and torques are applied on both ends of the box beam. The accuracy of the nonlinear FEA results is verified by a comparison with previous predicted formulas. Based on the FEA results, the relationship between the residual ultimate strength and crack parameters can be indicated in a function with period of π in the form of Fourier series.

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