scholarly journals Modeling Palletized Products: The Case of Semi-Filled Bottles under Top-Load Conditions

2020 ◽  
Vol 10 (1) ◽  
pp. 332
Author(s):  
Ana Pavlovic ◽  
Cristiano Fragassa ◽  
Luca Vegliò ◽  
Felipe Vannucchi de Camargo ◽  
Giangiacomo Minak
Keyword(s):  
Experimental Data ◽  
Numerical Methods ◽  
Finite Elements ◽  
Large Deformations ◽  
Plastic Material ◽  
Material Models ◽  
Pet Bottles ◽  
Elastic Plastic Material ◽  
Complex Phenomena ◽  
Load Conditions

An investigation on numerical methods able to simplify the mechanical behavior of PET bottles, partially filled with liquid, under compression loadings is presented here. Compressive stress conditions on bottles are very common during their transportation and can be accompanied by large deformations and instabilities that can compromise the integrity of the pack, with the risk of significant damages. The present paper proposes two approaches, both based on finite elements, and with elastic-plastic material models properly defined with the scope of investigating the complex phenomena that take place during these loading conditions. Although not perfect in terms of accuracy, these numerical methods have been proven to be capable to predicti the transport-related integrity risks, showing results that agree with experimental data, especially during the initial phases of load compression.

scholarly journals Characterization of Impacts of Elastic-plastic Spheres

2020 ◽  
Vol 64 (2) ◽  
pp. 165-171
Author(s):  
Bence Szabó ◽  
Attila Kossa
Keyword(s):  
Plastic Material ◽  
Analytical Models ◽  
Material Models ◽  
Elastic Plastic ◽  
Analytical Functions ◽  
Elastic Plastic Material ◽  
Explicit Dynamic ◽  
The Impact ◽  
The Given

This work presents explicit dynamic finite element simulations of various impacts of elastic-plastic solid spheres with flat walls. Different  analytical models describing the mechanics of the impact phenomenon are also presented. Elastic and elastic-plastic material models for the sphere and the wall are considered during the analyses. The applicability of these different models is demonstrated and their accuracies are investigated. Closed-form analytical functions are proposed to describe the relationship between the initial velocity of the sphere and the investigated contact characteristics for the given material models. Analysis is carried out to study the effect of the friction coefficient as well as the angle of impact for various cases.

Advances in Design and Installation Analysis of Pipelines in Congested Areas With Rough Seabed Topography

2004 ◽  
Author(s):  
Svein Sævik ◽  
Egil Giertsen ◽  
Vidar Berntsen
Keyword(s):  
Plastic Material ◽  
Structural Response ◽  
Element Formulation ◽  
Material Models ◽  
Curved Pipe ◽  
Seabed Topography ◽  
Departure Angle ◽  
Elastic Plastic Material ◽  
Linear Geometry ◽  
Principle Of Virtual Displacements

The present paper addresses a method for simulation of deepwater pipeline installation in offshore fields with rough seabed topography focusing on verification of installation feasibility. The method enables 3D pipe lay analysis to be carried out as a set of subsequent static analyses where the vessel is moved forward automatically considering the restraints from lay vessel departure angle and arbitrarily curved pipe routing. The analysis includes the effect of seabed topography from survey data and variable seabed conditions. The numerical algorithm is seamlessly integrated with 3D graphics for visualization of both the seabed terrain and the structural response of the pipe as the vessel is moving forward. The numerical method is based on finite elements that are formulated by applying the Principle of Virtual Displacements. Large deformations, non-linear geometry and contact effects are taken into account. In addition, elastic and elastic-plastic material models are allowed for, both for the pipe and the seabed contact elements. The paper focuses on the procedure including a brief theory description addressing the specialities needed in this case with respect to kinematics, material models and finite element formulation. The developed procedure is then demonstrated both by analytical and real pipeline installation test examples.

Extraction of elastic–plastic material properties of thin films through nanoindentaion technique with support of numerical methods

2011 ◽  
Vol 51 (6) ◽  
pp. 1046-1053 ◽  
Author(s):  
Łukasz Dowhań ◽  
Artur Wymysłowski ◽  
Paweł Janus ◽  
Magdalena Ekwińska ◽  
Olaf Wittler
Keyword(s):  
Thin Films ◽  
Numerical Methods ◽  
Material Properties ◽  
Plastic Material ◽  
Elastic Plastic ◽  
Elastic Plastic Material

Stress Optical Behavior of Rubber Networks at Large Deformations

1966 ◽  
Vol 39 (5) ◽  
pp. 1436-1450
Author(s):  
K. J. Smith ◽  
D. Puett
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Statistical Theory ◽  
Natural Rubber ◽  
Large Deformations ◽  
Strong Support ◽  
Theoretical Development ◽  
Statistical Parameters ◽  
Strain Behavior ◽  
Optical Behavior

Abstract The birefringence of natural rubber networks at large deformations has been investigated experimentally and compared with the simultaneously determined stress—strain behavior. Our data is analyzed using a statistical theory of flexibly jointed chains, derived herein, which is believed to be more significant for the particular range of deformation used than the theories of Treloar and of Kuhn and Grün. In addition, the experimental data of Saunders is commented on in light of our theoretical development. We find that for network extensions exceeding those of the Gaussian region there is little correlation between the observed and theoretical behavior of the stress and birefringence (based upon the theory of flexibly jointed chains) and this lack of agreement is attributed to the fact that the statistical parameters needed for the description of the optical chain properties differ in magnitude from those required for the mechanical properties. Furthermore, by considering the points of incipient crystallization the strain behavior of the stress-optical coefficient is highly indicative of nonGaussian behavior rather than crystallization, and therefore yields strong support for the position that nonGaussian behavior does exist in rubber networks.

scholarly journals Material parameter identification using finite elements with time-adaptive higher-order time integration and experimental full-field strain information

2021 ◽  
Author(s):  
Stefan Hartmann ◽  
Rose Rogin Gilbert
Keyword(s):  
Experimental Data ◽  
Finite Elements ◽  
Parameter Identification ◽  
Material Parameter ◽  
Measurement Data ◽  
Least Square ◽  
Image Correlation ◽  
Field Strain ◽  
Material Parameter Identification ◽  
Full Field

AbstractIn this article, we follow a thorough matrix presentation of material parameter identification using a least-square approach, where the model is given by non-linear finite elements, and the experimental data is provided by both force data as well as full-field strain measurement data based on digital image correlation. First, the rigorous concept of semi-discretization for the direct problem is chosen, where—in the first step—the spatial discretization yields a large system of differential-algebraic equation (DAE-system). This is solved using a time-adaptive, high-order, singly diagonally-implicit Runge–Kutta method. Second, to study the fully analytical versus fully numerical determination of the sensitivities, required in a gradient-based optimization scheme, the force determination using the Lagrange-multiplier method and the strain computation must be provided explicitly. The consideration of the strains is necessary to circumvent the influence of rigid body motions occurring in the experimental data. This is done by applying an external strain determination tool which is based on the nodal displacements of the finite element program. Third, we apply the concept of local identifiability on the entire parameter identification procedure and show its influence on the choice of the parameters of the rate-type constitutive model. As a test example, a finite strain viscoelasticity model and biaxial tensile tests applied to a rubber-like material are chosen.

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