Data-Driven Design Optimization for Composite Material Characterization

2011 ◽  
Vol 11 (2) ◽  
Author(s):  
John G. Michopoulos ◽  
John C. Hermanson ◽  
Athanasios Iliopoulos ◽  
Samuel G. Lambrakos ◽  
Tomonari Furukawa
Keyword(s):  
Energy Density ◽  
Design Optimization ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Polymer Matrix Composites ◽  
Large Strain ◽  
Surface Strain ◽  
Structural Shape ◽  
Material Systems ◽  
The Difference

The main goal of the present paper is to demonstrate the value of design optimization beyond its use for structural shape determination in the realm of the constitutive characterization of anisotropic material systems such as polymer matrix composites with or without damage. The approaches discussed are based on the availability of massive experimental data representing the excitation and response behavior of specimens tested by automated mechatronic material testing systems capable of applying multiaxial loading. Material constitutive characterization is achieved by minimizing the difference between experimentally measured and analytically computed system responses as described by surface strain and strain energy density fields. Small and large strain formulations based on additive strain energy density decompositions are introduced and utilized for constructing the necessary objective functions and their subsequent minimization. Numerical examples based on both synthetic (for one-dimensional systems) and actual data (for realistic 3D material systems) demonstrate the successful application of design optimization for constitutive characterization.

On the Constitutive Response Characterization for Composite Materials via Data-Driven Design Optimization

2011 ◽  
Author(s):  
John G. Michopoulos ◽  
John G. Hermanson ◽  
Athanasios Iliopoulos ◽  
Samuel Lambrakos ◽  
Tomonari Furukawa
Keyword(s):  
Composite Materials ◽  
Design Optimization ◽  
Strain Energy ◽  
Polymer Matrix Composites ◽  
Large Strain ◽  
Surface Strain ◽  
Matrix Composites ◽  
Constitutive Response ◽  
The Difference

In the present paper we focus on demonstrating the use of design optimization for the constitutive characterization of anisotropic material systems such as polymer matrix composites, with or without damage. All approaches are based on the availability of experimental data originating from mechatronic material testing systems that can expose specimens to multidimensional loading paths and can automate the acquisition of data representing the excitation and response behavior of the specimens involved. Material characterization is achieved by minimizing the difference between experimentally measured and analytically computed system responses as described by strain fields and surface strain energy densities. A one dimensional model is presented first to elucidate the design optimization for the general non-linear constitutive response. Small and large strain formulations based on strain energy density decompositions are developed and utilized for determining the constitutive behavior of composite materials. Examples based on both synthetic and actual data demonstrate the successful application of design optimization for constitutive characterization.

scholarly journals Volume free strain energy density method for applications to blunt V-notches

2020 ◽  
Vol 28 ◽  
pp. 734-742
Author(s):  
Pietro Foti ◽  
Seyed Mohammad Javad Razavi ◽  
Liviu Marsavina ◽  
Filippo Berto
Keyword(s):  
Energy Density ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Density Method ◽  
Free Strain

scholarly journals On the application of the volume free strain energy density method to blunt V-notches under mixed mode condition

2021 ◽  
Vol 230 ◽  
pp. 111716
Author(s):  
Pietro Foti ◽  
Seyed Mohammad Javad Razavi ◽  
Majid Reza Ayatollahi ◽  
Liviu Marsavina ◽  
Filippo Berto
Keyword(s):  
Energy Density ◽  
Strain Energy Density ◽  
Mixed Mode ◽  
Strain Energy ◽  
Density Method ◽  
Free Strain

scholarly journals Alternative derivation of the higher-order constitutive model for six-parameter elastic shells

2021 ◽  
Vol 72 (2) ◽  
Author(s):  
Mircea Bîrsan
Keyword(s):  
Energy Density ◽  
Constitutive Model ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Shell Theory ◽  
Constitutive Relations ◽  
Three Dimensional ◽  
Classical Shell Theory ◽  
Three Dimensional Elasticity ◽  
General Method

AbstractIn this paper, we present a general method to derive the explicit constitutive relations for isotropic elastic 6-parameter shells made from a Cosserat material. The dimensional reduction procedure extends the methods of the classical shell theory to the case of Cosserat shells. Starting from the three-dimensional Cosserat parent model, we perform the integration over the thickness and obtain a consistent shell model of order $$ O(h^5) $$ O ( h 5 ) with respect to the shell thickness h. We derive the explicit form of the strain energy density for 6-parameter (Cosserat) shells, in which the constitutive coefficients are expressed in terms of the three-dimensional elasticity constants and depend on the initial curvature of the shell. The obtained form of the shell strain energy density is compared with other previous variants from the literature, and the advantages of our constitutive model are discussed.

Storing Energy in the Mechanical Domain

2014 ◽  
Vol 1679 ◽  
Author(s):  
O.G. Súchil ◽  
G. Abadal ◽  
F. Torres
Keyword(s):  
Energy Source ◽  
Energy Density ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Critical Strain ◽  
Substrate Surface ◽  
Maximum Load ◽  
Linear Buckling ◽  
Initial Ph ◽  
Self Powered

ABSTRACTSelf-powered microsystems as an alternative to standard systems powered by electrochemical batteries are taking a growing interest. In this work, we propose a different method to store the energy harvested from the ambient which is performed in the mechanical domain. Our mechanical storage concept is based on a spring which is loaded by the force associated to the energy source to be harvested [1]. The approach is based on pressing an array of fine wires (fws) grown vertically on a substrate surface. For the fine wires based battery, we have chosen ZnO fine wires due the fact that they could be grown using a simple and cheap process named hydrothermal method [2]. We have reported previous experiments changing temperature and initial pH of the solution in order to determine the best growth [3]. From new experiments done varying the compounds concentration the best results of fine wires were obtained. To characterize these fine wires we have considered that the maximum load we can apply to the system is limited by the linear buckling of the fine wires. From the best results we obtained a critical strain of εc = 3.72 % and a strain energy density of U = 11.26 MJ/m3, for a pinned-fixed configuration [4].

On the Crack Initiated from the Bi-Material Notch Tip

2010 ◽  
Vol 452-453 ◽  
pp. 441-444 ◽  
Author(s):  
Tomáš Profant ◽  
Jan Klusák ◽  
Michal Kotoul
Keyword(s):  
Energy Density ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Local Minimum ◽  
Plane Elasticity ◽  
Mean Value ◽  
Tangential Stresses ◽  
Density Factor ◽  
The Mean ◽  
Energy Density Factor

The bi-material notch composed of two orthotropic parts is considered. The radial and tangential stresses and strain energy density is expressed using the Stroh-Eshelby-Lekhnitskii formalism for the plane elasticity. The potential direction of the crack initiation is determined from the maximum mean value of the tangential stresses and local minimum of the mean value of the generalized strain energy density factor in both materials. Matched asymptotic procedure is used to derive the change of potential energy for the debonding crack and the crack initiated in the determined direction.

Application of the Strain Energy Density Criterion to the Estimation of Fracture Loads in Structural Steel S355J2 at Lower Shelf Temperatures

2017 ◽  
Author(s):  
Sergio Cicero ◽  
Francisco Ibáñez ◽  
Isabela Procopio ◽  
Virginia Madrazo
Keyword(s):  
Energy Density ◽  
Structural Steel ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Input Parameter ◽  
Fracture Load ◽  
Notched Specimens ◽  
Fracture Tests ◽  
Material Fracture ◽  
Cracked Specimens

This paper presents the application of the Strain Energy Density (SED) criterion to the estimation of fracture loads on structural steel S355J2 operating at lower shelf temperatures (−196°C) and containing U-shaped notches. 24 fracture tests were performed on this material, combining 6 different notch radii: 0 mm (crack-like defect), 0.15 mm, 0.25 mm, 0.50 mm, 1.0 mm and 2.0 mm. The results obtained in cracked specimens (0 mm notch radius) were used to determine the material fracture toughness, which is an input parameter in the SED criterion, whereas the notched specimens were used to demonstrate the capacity and the limitations of the SED criterion to provide fracture load estimations in the analyzed conditions.

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