scholarly journals Investigation of failure initiation in curved composite laminates using a higher-order beam model

2017 ◽  
Vol 168 ◽  
pp. 143-152 ◽  
Author(s):  
C. Thurnherr ◽  
R.M.J. Groh ◽  
P. Ermanni ◽  
P.M. Weaver
Keyword(s):  
Composite Laminates ◽  
Higher Order ◽  
Beam Model ◽  
Failure Initiation

scholarly journals Effect of Slam Force Duration on the Vibratory Response of a Lightweight High-Speed Wave-Piercing Catamaran

2015 ◽  
Vol 59 (02) ◽  
pp. 69-84
Author(s):  
Jason John McVicar ◽  
Jason Lavroff ◽  
Michael Richard Davis ◽  
Giles Thomas
Keyword(s):  
High Speed ◽  
Bending Strength ◽  
Experimental Studies ◽  
Bending Moment ◽  
Higher Order ◽  
Acute Angle ◽  
Beam Model ◽  
Higher Order Modes ◽  
Hull Structure ◽  
Vertical Bending Moment

When the surface of a ship meets the water surface at an acute angle with a high relative velocity, significant short-duration forces can act on the hull plating. Such an event is referred to as a slam. Slam loads imparted on ships are generally considered to be of an impulsive nature. As such, slam loads induce vibration in the global hull structure that has implications for both hull girder bending strength and fatigue life of a vessel. A modal method is often used for structural analysis whereby higher order modes are neglected to reduce computational effort. The effect of the slam load temporal distribution on the whipping response and vertical bending moment are investigated here by using a continuous beam model with application to a 112 m INCAT wave-piercing catamaran and correlation to full-scale and model-scale experimental data. Experimental studies have indicated that the vertical bending moment is dominated by the fundamental longitudinal bending mode of the structure. However, it is shown here that although the fundamental mode is dominant in the global structural response, the higher order modes play a significant role in the early stages of the response and may not be readily identifiable if measurements are not taken sufficiently close to the slam location. A relationship between the slam duration and the relative modal response magnitudes is found, which is useful in determining the appropriate truncation of a modal solution.

Damage Modeling and Detection in Smart Composites

2000 ◽  
Author(s):  
Aditi Chattopadhyay ◽  
Dan Dragomir-Daescu
Keyword(s):  
Composite Laminates ◽  
Composite Structures ◽  
Piezoelectric Materials ◽  
Piezoelectric Actuators ◽  
Order Theory ◽  
Higher Order ◽  
Damage Indices ◽  
Higher Order Theory ◽  
Extent Of Damage ◽  
Reliability And Robustness

Abstract The presence of damage in structures made out of composite and/or piezoelectric materials can cause significant degradation in structural performance. In the present paper, damage indices based on two-dimensional gapped smoothing technique and model strains are developed in order to enhance the accuracy in predicting the location and extent of damage in composite structures. Structural analysis is performed based on a refined higher order theory, which can capture the transverse shear effects in anisotropic laminates. An approach using the developed damage indices and the laminate model of the higher order theory is employed to model and identify delaminations in composite laminates. It is also used in the delamination analysis of composite laminates with piezoelectric actuators. The proposed modal strain based damage indexes are used to perform delamination analysis. Comparison study is performed to illustrate that the reliability and robustness of the new proposed damage indices in locating delaminations in composite and smart composite structures. The effects on modal strain and damage indices due to the presence of surface bounded piezoelectric actuators are also presented and discussed.

A New Hyperbolic Two-Unknown Beam Model for Bending and Buckling Analysis of a Nonlocal Strain Gradient Nanobeams

2019 ◽  
Vol 57 ◽  
pp. 175-191 ◽  
Author(s):  
Wafa Adda Bedia ◽  
Mohammed Sid Ahmed Houari ◽  
Aicha Bessaim ◽  
Abdelmoumen Anis Bousahla ◽  
Abdelouahed Tounsi ◽  
...  
Keyword(s):  
Shear Deformation ◽  
Strain Gradient ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
Beam Theory ◽  
Higher Order ◽  
Buckling Analysis ◽  
Strain Gradient Theory ◽  
Beam Model ◽  
Nonlocal Strain Gradient

In present paper, a novel two variable shear deformation beam theories are developed and applied to investigate the combined effects of nonlocal stress and strain gradient on the bending and buckling behaviors of nanobeams by using the nonlocal strain gradient theory. The advantage of this theory relies on its two-unknown displacement field as the Euler-Bernoulli beam theory, and it is capable of accurately capturing shear deformation effects, instead of three as in the well-known first shear deformation theory and higher-order shear deformation theory. A shear correction factor is, therefore, not needed. Equations of motion are obtained via Hamilton’s principle. Analytical solutions for the bending and buckling analysis are given for simply supported beams. Efficacy of the proposed model is shown through illustrative examples for bending buckling of nanobeams. The numerical results obtained are compared with those of other higher-order shear deformation beam theory. The results obtained are found to be accurate. Verification studies show that the proposed theory is not only accurate and simple in solving the bending and buckling behaviour of nanobeams, but also comparable with the other shear deformation theories which contain more number of unknowns

scholarly journals A new higher-order elastoplastic beam model for reinforced concrete

Meccanica ◽  
2019 ◽  
Vol 55 (4) ◽  
pp. 791-813 ◽  
Author(s):  
G. Corre ◽  
A. Lebée ◽  
K. Sab ◽  
M. K. Ferradi ◽  
X. Cespedes
Keyword(s):  
Reinforced Concrete ◽  
Higher Order ◽  
Beam Model ◽  
Elastoplastic Beam
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