Design with Nonhomogeneous Materials—Part III: Shear Effects in the Bending of Thin-Walled Prismatic Beams

1987 ◽  
Vol 109 (1) ◽  
pp. 92-96 ◽  
Author(s):  
V. K. Stokes
Keyword(s):  
Material Properties ◽  
Elastic Moduli ◽  
Simple Theory ◽  
Pure Bending ◽  
Strongly Coupled ◽  
Shear Effects ◽  
Shear Strains ◽  
Thin Walled ◽  
Nonhomogeneous Materials

A simple theory, in which longitudinal and shear strains are not coupled, has been developed to account for shear effects in the bending of thin-walled nonhomogeneous prismatic beams. This extends the analysis for the pure bending of nonhomogeneous beams, for which the results are known to depend on average “elastic moduli” that are strongly coupled combinations of geometry and material properties. It is shown that shear effects can be analyzed without defining additional average moduli. This theory has been used for determining the shear centers of thin-walled sections.

Design with Nonhomogeneous Materials—Part I: Pure Bending of Prismatic Bars

1987 ◽  
Vol 109 (1) ◽  
pp. 82-86 ◽  
Author(s):  
V. K. Stokes
Keyword(s):  
Tensile Test ◽  
Material Properties ◽  
Elastic Moduli ◽  
Mechanical Response ◽  
Mechanical Design ◽  
Beam Theory ◽  
Pure Bending ◽  
Strongly Coupled ◽  
Point To Point ◽  
Nonhomogeneous Materials

Because material properties vary from point to point in nonhomogeneous materials, there is some question as to what “properties” are measured in tests such as the tensile test, and how such “properties” can be used in the mechanical design process. In this paper, the mechanical response of nonhomogeneous prismatic bars in pure bending has been shown to depend on parameters that are strongly coupled combinations of geometry and material properties. The purely geometry based inertia tensor in homogeneous beam theory is replaced in the nonhomogeneous case by the rigidity tensor, which combines geometry and material properties. Interpretations for the average elastic moduli, which would be determined by tests on nonhomogeneous materials, have been explored. Also discussed is the usefulness of such average moduli for predicting the mechanical response of nonhomogeneous bars.

A Simple Model for Cornering and Belt-edge Separation in Radial Tires

1986 ◽  
Vol 14 (1) ◽  
pp. 3-32 ◽  
Author(s):  
P. Popper ◽  
C. Miller ◽  
D. L. Filkin ◽  
W. J. Schaffers
Keyword(s):  
Simple Model ◽  
Transverse Shear ◽  
Mathematical Analysis ◽  
Pure Bending ◽  
Radial Tire ◽  
Optimum Angle ◽  
Shear Strains ◽  
Interlaminar Shear ◽  
Edge Separation ◽  
Shear Bending

Abstract A mathematical analysis of radial tire cornering was performed to predict tire deflections and belt-edge separation strains. The model includes the effects of pure bending, transverse shear bending, lateral restraint of the carcass on the belt, and shear displacements between belt and carcass. It also provides a description of the key mechanisms that act during cornering. The inputs include belt and carcass cord properties, cord angle, pressure, rubber properties, and cornering force. Outputs include cornering deflections and interlaminar shear strains. Key relations found between tire parameters and responses were the optimum angle for minimum cornering deflections and its dependence on cord modulus, and the effect of cord angle and modulus on interlaminar shear strains.

The stability of rectangular thin-walled profile with loading according to the scheme of pure bending

2020 ◽  
pp. 41-45
Author(s):  
V.B. Zylev ◽  
◽  
P.O. Platnov ◽  
I.V. Alferov ◽  
◽  
...  
Keyword(s):  
Pure Bending ◽  
Thin Walled ◽  
The Stability

Temperature relaxation in strongly-coupled binary ionic mixtures

2021 ◽  
Author(s):  
Robert Sprenkle ◽  
Luciano Silvestri ◽  
M. S. Murillo ◽  
Scott Bergeson
Keyword(s):  
Material Properties ◽  
Inertial Confinement Fusion ◽  
Coulomb Systems ◽  
High Energy ◽  
High Energy Density ◽  
Inertial Confinement ◽  
Relaxation Rates ◽  
Strongly Coupled ◽  
Wide Range ◽  
Temperature Relaxation

Abstract New facilities such as the National Ignition Facility and the Linac Coherent Light Source have pushed the frontiers of high energy-density matter. These facilities offer unprecedented opportunities for exploring extreme states of matter, ranging from cryogenic solid-state systems to hot, dense plasmas, with applications to inertial-confinement fusion and astrophysics. However, significant gaps in our understanding of material properties in these rapidly evolving systems still persist. In particular, non-equilibrium transport properties of strongly-coupled Coulomb systems remain an open question. Here, we study ion-ion temperature relaxation in a binary mixture, exploiting a recently-developed dual-species ultracold neutral plasma. We compare measured relaxation rates with atomistic simulations and a range of popular theories. Our work validates the assumptions and capabilities of the simulations and invalidates theoretical models in this regime. This work illustrates an approach for precision determinations of detailed material properties in Coulomb mixtures across a wide range of conditions.

Computational Modeling and Energy Absorption Behavior of Thin-Walled Tubes with the Kresling Origami Pattern

2021 ◽  
Vol 62 (2) ◽  
pp. 71-81
Author(s):  
Jiaqiang Li ◽  
Yao Chen ◽  
Xiaodong Feng ◽  
Jian Feng ◽  
Pooya Sareh
Keyword(s):  
Energy Absorption ◽  
Material Properties ◽  
Rotation Angle ◽  
Programming Model ◽  
Mixed Integer ◽  
Element Analysis ◽  
Cross Sectional ◽  
Thin Walled Tube ◽  
Absorption Performance ◽  
Thin Walled

Origami structures have been widely used in various engineering fields due to their desirable properties such as geometric transformability and high specific energy absorption. Based on the Kresling origami pattern, this study proposes a type of thin-walled origami tube the structural configuration of which is found by a mixed-integer linear programming model. Using finite element analysis, a reasonable configuration of a thin-walled tube with the Kresling pattern is firstly analyzed. Then, the influences of different material properties, the rotation angle of the upper and lower sections of the tube unit, and cross-sectional shapes on the energy absorption behavior of the thin-walled tubes under axial compression are evaluated. The results show that the symmetric thin-walled tube with the Kresling pattern is a reasonable choice for energy absorption purposes. Compared with thin-walled prismatic tubes, the thin-walled tube with the Kresling pattern substantially reduces the initial peak force and the average crushing force, without significantly reducing its energy absorption capacity; moreover, it enters the plastic energy dissipation stage ahead of time, giving it a superior energy absorption performance. Besides, the material properties, rotation angle, and cross-sectional shape have considerable influences on its energy absorption performance. The results provide a basis for the application of the Kresling origami pattern in the design of thin-walled energy-absorbingstructures.

scholarly journals Experimental Investigations of Impact Damage Influence on Behavior of Thin-Walled Composite Beam Subjected to Pure Bending

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1127 ◽  
Author(s):  
Tomasz Kubiak ◽  
Lukasz Borkowski ◽  
Nina Wiacek
Keyword(s):  
Impact Damage ◽  
Full Range ◽  
Image Correlation ◽  
Bending Test ◽  
Beam Deflection ◽  
Experimental Investigations ◽  
Pure Bending ◽  
Channel Section ◽  
Thin Walled ◽  
The Impact

The paper deals with buckling, postbuckling, and failure of pre-damaged channel section beam subjected to pure bending. The channel section beams made of eight-layered GFRP laminate with different symmetrical layups have been considered. The specimens with initially pre-damaged web or flange were investigated to access the influence of impact damage on work of thin-walled structure in the full range of load till failure. The bending tests of initially pre-damage beams have been performed on a universal tensile machine with especially designed grips. The digital image correlation system allowing to follow the beam deflection have been employed. The experimentally obtained results are presented in graphs presenting load-deflection or load vs. angle of rotation relations and in photos presenting impact damages areas before and after bending test. The results show that the impact pre-damages have no significant influence on the work of channel section beams.

scholarly journals Modeling and Experimental Validation of the VARTM Process for Thin-Walled Preforms

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2003
Author(s):  
Da Wu ◽  
Ragnar Larsson ◽  
Mohammad S. Rouhi
Keyword(s):  
Shell Model ◽  
Computational Efficiency ◽  
Large Scale ◽  
Strongly Coupled ◽  
Thin Walled Structures ◽  
Simulation Based ◽  
Thin Walled ◽  
High Computational Efficiency ◽  
Insight Into ◽  
Vartm Process

In this paper, recent shell model is advanced towards the calibration and validation of the Vacuum-assisted Resin Transfer Molding (VARTM) process in a novel way. The model solves the nonlinear and strongly coupled resin flow and preform deformation when the 3-D flow and stress problem is simplified to a corresponding 2-D problem. In this way, the computational efficiency is enhanced dramatically, which allows for simulations of the VARTM process of large scale thin-walled structures. The main novelty is that the assumptions of the neglected through-thickness flow and the restricted preform deformation along the normal of preform surface suffice well for the thin-walled VARTM process. The model shows excellent agreement with the VARTM process experiment. With good accuracy and high computational efficiency, the shell model provides an insight into the simulation-based optimization of the VARTM process. It can be applied to either determine locations of the gate and vents or optimize process parameters to reduce the deformation.

Influence of Mechanical Stress at High Temperatures on the Properties of Steels Intended for the Manufacture of Fuel Cladding for Generation IV Reactors

2017 ◽  
Vol 270 ◽  
pp. 246-252
Author(s):  
Zbyněk Špirit ◽  
Michal Chocholoušek ◽  
Marek Šíma
Keyword(s):  
Mechanical Stress ◽  
Material Properties ◽  
Fracture Mechanism ◽  
Nuclear Reactors ◽  
Mechanical Tests ◽  
Basic Material ◽  
Oxide Dispersion ◽  
Fuel Cladding ◽  
Thin Walled ◽  
Miniature Specimens

This paper describes the testing of thin-walled tubes made of oxide dispersion-hardened steels based on yttrium oxides. Series of mechanical and metallographic tests were carried out on the steels to evaluate the basic material properties. These steels are the candidate materials for the manufacture of the fuel cladding for generation IV nuclear reactors. Mechanical tests were performed on miniature specimens of Fe-9Cr and Fe-14Cr steels at 20 °C, 500 °C, and 625 °C under vacuum. Metallographic, fractographic and EBSD analyses were used to describe microstructure and fracture mechanism of the tested materials.

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