Postbuckling mechanics in slender steel plates under pure shear: A focus on boundary conditions and load path

In this study, for behavior of steel plate which subjected to uniform blast loading the general purpose finite element software ABAQUS, was used. The aim of this paper is to recognize the effect of stiffener configurations, boundary conditions, mesh dependency, load patterns, geometry of plates and damping on dynamic response of the plates. Special emphasis is focused on the evolution of mid-point displacements. The results show that stiffener configuration and boundary conditions have a significant influence on the response, while the effects of damping and load pattern on maximum response are negligible. The results obtained allow an insight into the effect of stiffener configurations and other parameters on the response of the plates under uniform blast loading.

Download Full-text

Geopolymerics Adhesives for Joint Steel Plates

Materials Science Forum ◽

10.4028/www.scientific.net/msf.758.133 ◽

2013 ◽

Vol 758 ◽

pp. 133-137

Author(s):

Kelly Cristiane Gomes ◽

Elder Cunha de Lira ◽

Andre R.R. de Sousa ◽

Marçal Rosas ◽

Sandro Marden Torrres ◽

...

Keyword(s):

Thermal Expansion ◽

Mixed Mode ◽

Physical Phenomenon ◽

Pure Shear ◽

Steel Plates ◽

Structural Bonding ◽

Weathered Soil ◽

Metal Plates ◽

Differential Thermal Expansion ◽

Flexure Test

The process of bonding degradation throughout the whole loading phase up to the total collapse has been investigated by models of interlaminar degradation in composite materials and subsequently adapted to the problem of structural bonding. The physical phenomenon represented by these models is exactly the same that must be studied in the case of metal plates adhered with geopolymers: the adhesion between substrates. In this work, it was investigated the adherence of joint steel plates through propagation tests of clefts in mixed mode MMF (Mixed-Mode Flexure Test) which combine the efforts of traction (due to differential thermal expansion) and shear (due the slipping and preassure due the own weight of the adhered layers), in other words, modes I (pure opening) and II (pure shear) of propagation, being one of the most common glued plates. It was used two types of geopolymeric adhesives (one made of metakaolinite and another with weathered soil) activated with sodium silicate. The bonded systems were subjected to temperatures between 55°C and 600°C in order to evaluate its potential against the use of epoxy-based adhesives. The substrates used were steel. In general, the adhesives made of metakaolinite had better adhesion.

Download Full-text

Dynamic recrystallization during deformation of polycrystalline ice: insights from numerical simulations

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2015.0346 ◽

2017 ◽

Vol 375 (2086) ◽

pp. 20150346 ◽

Cited By ~ 16

Author(s):

Maria-Gema Llorens ◽

Albert Griera ◽

Florian Steinbach ◽

Paul D. Bons ◽

Enrique Gomez-Rivas ◽

...

Keyword(s):

Boundary Conditions ◽

Dynamic Recrystallization ◽

Numerical Simulations ◽

Simple Shear ◽

Basal Slip ◽

Pure Shear ◽

Ice Sheets ◽

Shear Direction ◽

Slip Systems ◽

Ice Sheet Dynamics

The flow of glaciers and polar ice sheets is controlled by the highly anisotropic rheology of ice crystals that have hexagonal symmetry (ice lh). To improve our knowledge of ice sheet dynamics, it is necessary to understand how dynamic recrystallization (DRX) controls ice microstructures and rheology at different boundary conditions that range from pure shear flattening at the top to simple shear near the base of the sheets. We present a series of two-dimensional numerical simulations that couple ice deformation with DRX of various intensities, paying special attention to the effect of boundary conditions. The simulations show how similar orientations of c -axis maxima with respect to the finite deformation direction develop regardless of the amount of DRX and applied boundary conditions. In pure shear this direction is parallel to the maximum compressional stress, while it rotates towards the shear direction in simple shear. This leads to strain hardening and increased activity of non-basal slip systems in pure shear and to strain softening in simple shear. Therefore, it is expected that ice is effectively weaker in the lower parts of the ice sheets than in the upper parts. Strain-rate localization occurs in all simulations, especially in simple shear cases. Recrystallization suppresses localization, which necessitates the activation of hard, non-basal slip systems. This article is part of the themed issue ‘Microdynamics of ice’.

Download Full-text

Tuning and Emulation of Mechanical Characteristics – Tunable Mounts and a Mechanical Hardware-in-the-Loop Approach for More Efficient Research and Testing

Lecture Notes in Mechanical Engineering - Uncertainty in Mechanical Engineering ◽

10.1007/978-3-030-77256-7_12 ◽

2021 ◽

pp. 129-144

Author(s):

Jonathan Millitzer ◽

Jan Hansmann ◽

Giovanni Lapiccirella ◽

Christoph Tamm ◽

Sven Herold

Keyword(s):

Boundary Conditions ◽

Mechanical Characteristics ◽

Numerical Models ◽

Parameter Variation ◽

Hardware In The Loop ◽

Load Path ◽

Active System ◽

Physical Experiments ◽

Short Period ◽

Body In White

AbstractNumerical simulations offer a wide range of benefits, therefore they are widely used in research and development. One of the biggest benefits is the possibility of automated parameter variation. This allow testing different scenarios in a very short period of time. Nevertheless, physical experiments in the laboratory or on a test rig are still necessary and will still be necessary in the future. The physical experiments offer benefits e.g. for very complex and/or nonlinear systems and are needed for the validation of numerical models.Fraunhofer LBF has developed hardware solutions to bring the benefit of rapid and automated parameter variation to experimental environments. These solutions allow the tuning and emulation of the mechanical properties, like stiffness, damping and eigenfrequencies of structures.The work presents two approaches: First a stiffness tunable mount, which has been used in laboratory tests in the field of semi-active load path redistribution. It allowed the researcher to test the semi-active system under different mechanical boundary conditions in a short period of time. Second, a mechanical Hardware-in-the-loop (mHIL) approach for the NVH development of vehicles components is presented. Here a mHIL-system is used to emulate the mechanical characteristics of a vehicle’s body in white in a wide frequency range. This allows the experimental NVH optimization of vehicle components under realistic boundary conditions, without actually needing a (prototype) body in white.

Download Full-text

INELASTIC BUCKLING OF RECTANGULAR STEEL PLATES USING A RAYLEIGH–RITZ METHOD

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455403001026 ◽

2003 ◽

Vol 03 (04) ◽

pp. 503-521 ◽

Cited By ~ 5

Author(s):

S. T. SMITH ◽

M. A. BRADFORD ◽

D. J. OEHLERS

Keyword(s):

Boundary Conditions ◽

Yield Criterion ◽

Ritz Method ◽

Local Buckling ◽

Plate Boundary ◽

Displacement Function ◽

Steel Plates ◽

Flow Rule ◽

Various Boundary Conditions ◽

Applied Loading

The paper presents a Rayleigh–Ritz based non-discretization method of analysis for the inelastic local buckling of rectangular steel plates subjected to applied in-plane axial, bending and shear actions with various boundary conditions. Use is made of the pb-2 representation of the displacement function as the product of a domain polynomial and a boundary polynomial. The constitutive model for the plate is an adaptation of the von Mises yield criterion and the associated flow rule presented in an infinitesimal form, and which leads to an incremental and iterative method of solution. The convergence and accuracy of the solutions are demonstrated, and it is shown that the method of analysis is computationally feasible for the solution of inelastic bifurcative plate instability problems. A parametric study is then undertaken for a range of plate boundary conditions under various regimes of applied loading.

Download Full-text

Shape fabric development in rigid clast populations under pure shear: The influence of no-slip versus slip boundary conditions

Tectonophysics ◽

10.1016/j.tecto.2015.08.003 ◽

2015 ◽

Vol 659 ◽

pp. 63-69 ◽

Cited By ~ 4

Author(s):

Kieran F. Mulchrone ◽

Patrick A. Meere

Keyword(s):

Boundary Conditions ◽

Pure Shear ◽

Slip Boundary Conditions ◽

Slip Boundary

Download Full-text

Use of the Magnetostatic Analogue In Electromagnetic Lens Engineering

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100068795 ◽

1970 ◽

Vol 28 ◽

pp. 360-361

Author(s):

John W. Coleman

Keyword(s):

Boundary Conditions ◽

High Performance ◽

Force Fields ◽

Optical Design ◽

Direct Conversion ◽

Design Engineering ◽

Design Data ◽

Scalar Potentials ◽

Geometric Elements ◽

At Will

In the design engineering of high performance electromagnetic lenses, the direct conversion of electron optical design data into drawings for reliable hardware is oftentimes difficult, especially in terms of how to mount parts to each other, how to tolerance dimensions, and how to specify finishes. An answer to this is in the use of magnetostatic analytics, corresponding to boundary conditions for the optical design. With such models, the magnetostatic force on a test pole along the axis may be examined, and in this way one may obtain priority listings for holding dimensions, relieving stresses, etc..The development of magnetostatic models most easily proceeds from the derivation of scalar potentials of separate geometric elements. These potentials can then be conbined at will because of the superposition characteristic of conservative force fields.

Download Full-text