A pseudo-elastic material damage model, part I: Strain energy density criterion

1985 ◽  
Vol 3 (3) ◽  
pp. 193-207 ◽  
Author(s):  
P. Matic ◽  
G.C. Sih
Keyword(s):  
Energy Density ◽  
Elastic Material ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Damage Model ◽  
Material Damage

A unified damage model for fibrous composite laminae subject to in-plane stress-state and having multi material-nonlinearity

2020 ◽  
Vol 29 (9) ◽  
pp. 1329-1344
Author(s):  
GA Abu-Farsakh ◽  
AM Asfa
Keyword(s):  
Energy Density ◽  
Plastic Strain ◽  
Strain Energy Density ◽  
Damage Evolution ◽  
Strain Energy ◽  
Fibrous Composite ◽  
Damage Model ◽  
Damage Propagation ◽  
Damage Response ◽  
Plastic Strain Energy

In the present study, a novel methodology of damage modeling is introduced to predict damage propagation in fibrous composite materials according to the plastic strain energy density induced in the lamina only. The importance of the new damage-model is the ability to assess damage-evolution in fibrous composite laminae irrespective of stress-state and fiber-orientation angle. An energy-based model called as a unified damage model, is proposed to evaluate damage in unidirectional fibrous composite laminae. The aforementioned damage model represents a unique relationship between damage-evolution and the resulting plastic strain energy density induced in the composite lamina, as verified through this study. Damage propagation under a state of in-plane-stress is investigated for three composite laminas; boron/epoxy, graphite/epoxy, and carbon/epoxy. The unified damage model represents a simplified mathematical relation of quantum-damage (or modified-damage) variables in terms of the induced plastic-strain-energy density induced in a composite lamina. The developed unified damage model confirms the results of Ghazi-Ahmad macro-mechanical damage model in which graphite/epoxy has the lowest damage response, whereas boron/epoxy has the highest possible damage response amongst the three composite materials. Also, it is noticed that quantum-damage propagates nonlinearly with the evolved plastic strain energy density in fibrous composite laminae.

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.

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