Stress–strain analysis of dented rectangular plates subjected to uni-axial compressive loading

2015 ◽  
Vol 99 ◽  
pp. 78-91 ◽  
Author(s):  
S. Saad-Eldeen ◽  
Y. Garbatov ◽  
C. Guedes Soares
Keyword(s):  
Compressive Loading ◽  
Strain Analysis ◽  
Rectangular Plates ◽  
Stress Strain

Stress-strain analysis of singularly loaded rectangular plates sealing a pool of liquid

1969 ◽  
Vol 4 (4) ◽  
pp. 287-296
Author(s):  
L E El-Bayoumy ◽  
H H Pan
Keyword(s):  
Rectangular Plate ◽  
Great Influence ◽  
Strain Analysis ◽  
Rectangular Plates ◽  
Bending Moments ◽  
Stress Strain ◽  
Submerged Plate

The bending problem of a concentratedly loaded rectangular plate sealing a pool of liquid is investigated. Both cases, the submerged plate and the unsubmerged plate, are considered in detail. It is found that the compressibility of the sealed liquid has great influence on the deflections and the bending moments of the plates. Examples of various cases are given and illustrated by a number of graphs.

Delamination in the scoring and folding of paperboard

TAPPI Journal ◽  
2012 ◽  
Vol 11 (1) ◽  
pp. 61-66 ◽  
Author(s):  
DOEUNG D. CHOI ◽  
SERGIY A. LAVRYKOV ◽  
BANDARU V. RAMARAO
Keyword(s):  
Finite Element ◽  
Plane Deformation ◽  
Strain Analysis ◽  
Local Strain ◽  
Uniaxial Stress ◽  
Material Model ◽  
Element Model ◽  
Plastic Behavior ◽  
Stress Strain ◽  
Strain Fields

Delamination between layers occurs during the creasing and subsequent folding of paperboard. Delamination is necessary to provide some stiffness properties, but excessive or uncontrolled delamination can weaken the fold, and therefore needs to be controlled. An understanding of the mechanics of delamination is predicated upon the availability of reliable and properly calibrated simulation tools to predict experimental observations. This paper describes a finite element simulation of paper mechanics applied to the scoring and folding of multi-ply carton board. Our goal was to provide an understanding of the mechanics of these operations and the proper models of elastic and plastic behavior of the material that enable us to simulate the deformation and delamination behavior. Our material model accounted for plasticity and sheet anisotropy in the in-plane and z-direction (ZD) dimensions. We used different ZD stress-strain curves during loading and unloading. Material parameters for in-plane deformation were obtained by fitting uniaxial stress-strain data to Ramberg-Osgood plasticity models and the ZD deformation was modeled using a modified power law. Two-dimensional strain fields resulting from loading board typical of a scoring operation were calculated. The strain field was symmetric in the initial stages, but increasing deformation led to asymmetry and heterogeneity. These regions were precursors to delamination and failure. Delamination of the layers occurred in regions of significant shear strain and resulted primarily from the development of large plastic strains. The model predictions were confirmed by experimental observation of the local strain fields using visual microscopy and linear image strain analysis. The finite element model predicted sheet delamination matching the patterns and effects that were observed in experiments.

Stress-Strain Analysis and Simulation for Estimation of Cutting Forces on the Skin

2015 ◽  
Vol 9 (6) ◽  
pp. 583
Author(s):  
Dario German Buitrago ◽  
Luis Carlos Ruíz ◽  
Olga Lucia Ramos
Keyword(s):  
Cutting Forces ◽  
Strain Analysis ◽  
Stress Strain

A machine learning approach to estimate the strain energy absorption in expanded polystyrene foams

2021 ◽  
pp. 0021955X2110210
Author(s):  
Alejandro E Rodríguez-Sánchez ◽  
Héctor Plascencia-Mora
Keyword(s):  
Neural Network ◽  
Energy Absorption ◽  
Mechanical Energy ◽  
Compressive Loading ◽  
Ground Truth ◽  
Expanded Polystyrene ◽  
Polystyrene Foam ◽  
Stress Strain ◽  
Ground Truth Data ◽  
Expanded Polystyrene Foam

Traditional modeling of mechanical energy absorption due to compressive loadings in expanded polystyrene foams involves mathematical descriptions that are derived from stress/strain continuum mechanics models. Nevertheless, most of those models are either constrained using the strain as the only variable to work at large deformation regimes and usually neglect important parameters for energy absorption properties such as the material density or the rate of the applying load. This work presents a neural-network-based approach that produces models that are capable to map the compressive stress response and energy absorption parameters of an expanded polystyrene foam by considering its deformation, compressive loading rates, and different densities. The models are trained with ground-truth data obtained in compressive tests. Two methods to select neural network architectures are also presented, one of which is based on a Design of Experiments strategy. The results show that it is possible to obtain a single artificial neural networks model that can abstract stress and energy absorption solution spaces for the conditions studied in the material. Additionally, such a model is compared with a phenomenological model, and the results show than the neural network model outperforms it in terms of prediction capabilities, since errors around 2% of experimental data were obtained. In this sense, it is demonstrated that by following the presented approach is possible to obtain a model capable to reproduce compressive polystyrene foam stress/strain data, and consequently, to simulate its energy absorption parameters.

Stress Analysis of Pipeline Subjected to Differential Frost Heave

2013 ◽  
Author(s):  
Yan Di ◽  
Jian Shuai ◽  
Lingzhen Kong ◽  
Xiayi Zhou
Keyword(s):  
Strain Analysis ◽  
Element Model ◽  
Frozen Soil ◽  
Computational Method ◽  
Frost Heave ◽  
Safe Operation ◽  
Stress Strain ◽  
Segregation Potential ◽  
Differential Frost Heave ◽  
Design Construction

Frost heave must be considered in cases where pipelines are laid in permafrost in order to protect the pipelines from overstress and to maintain the safe operation. In this paper, a finite element model for stress/strain analysis in a pipeline subjected to differential frost heave was presented, in which the amount of frost heave is calculated using a segregation potential model and considering creep effects of the frozen soil. In addition, a computational method for the temperature field around a pipeline was proposed so that the frozen depth and temperature variation gradient could be obtained. Using the procedure proposed in this paper, stress/strain can be calculated according to the temperature on the surface of soil and in a pipeline. The result shows the characteristics of deformation and loading of a pipeline subjected to differential frost heave. In general, the methods and results in this paper can provide a reference for the design, construction and operation of pipelines in permafrost areas.

Numerical Modeling and Analytical Investigation of Autofrettage Process on the Fluid End Module of Fracture Pumps

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Mahdi Kiani ◽  
Roger Walker ◽  
Saman Babaeidarabad
Keyword(s):  
Residual Stresses ◽  
Kinematic Hardening ◽  
Analytical Formula ◽  
Strain Analysis ◽  
Material Model ◽  
Analytical Investigation ◽  
Stress Strain ◽  
Element Analysis ◽  
Hardening Material ◽  
Strain Evolution

One of the most important components in the hydraulic fracturing is a type of positive-displacement-reciprocating-pumps known as a fracture pump. The fluid end module of the pump is prone to failure due to unconventional drilling impacts of the fracking. The basis of the fluid end module can be attributed to cross bores. Stress concentration locations appear at the bores intersections and as a result of cyclic pressures failures occur. Autofrettage is one of the common technologies to enhance the fatigue resistance of the fluid end module through imposing the compressive residual stresses. However, evaluating the stress–strain evolution during the autofrettage and approximating the residual stresses are vital factors. Fluid end module geometry is complex and there is no straightforward analytical solution for prediction of the residual stresses induced by autofrettage. Finite element analysis (FEA) can be applied to simulate the autofrettage and investigate the stress–strain evolution and residual stress fields. Therefore, a nonlinear kinematic hardening material model was developed and calibrated to simulate the autofrettage process on a typical commercial triplex fluid end module. Moreover, the results were compared to a linear kinematic hardening model and a 6–12% difference between two models was observed for compressive residual hoop stress at different cross bore corners. However, implementing nonlinear FEA for solving the complicated problems is computationally expensive and time-consuming. Thus, the comparison between nonlinear FEA and a proposed analytical formula based on the notch strain analysis for a cross bore was performed and the accuracy of the analytical model was evaluated.

Stress – Strain Analysis on ZnO Nanostructures Synthesized via Wet Chemistry Method

2015 ◽  
Vol 1112 ◽  
pp. 57-61 ◽  
Author(s):  
Amalia Sholehah ◽  
Akhmad Herman Yuwono
Keyword(s):  
Crystallite Size ◽  
Strain Analysis ◽  
Xrd Analysis ◽  
Heating Process ◽  
Zno Nanostructures ◽  
Stress Strain ◽  
Wet Chemistry ◽  
Chemistry Method ◽  
Hall Method ◽  
Scherrer Equation

In the present work, ZnO nanostructures were synthesized via wet chemistry method. The seeding solution was prepared from zinc nitrate tetrahydrate and hexamethylenetetramine. Prior to the heating process, the seeding solution was immersed in cold bath (0°C). XRD analysis had shown sharp peaks in diffractogram, indicating the high crystallinity of ZnO nanostructures. The crystallite size was determined using Scherrer equation and Williamson-Hall method. Other relevant parameters including stress, strain, and energy density were calculated using Williamson-Hall assuming UDM, UDSM, and UDEDM. The results had revealed that crystallite size calculated with Williamson-Hall method is more accurate than Scherrer equation.

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