Stress Distribution on the Cracked Sandwich Plate with Non Linear Thermal and Moisture Concentration

The influence of linear and non-linear temperature and moisture concentration distribution on the stress distribution was studied for metal/ceramic sandwich plate with transverse cracks. An interlaminar adhesive layer between two different layers is taken into account which transferring the normal stress and the interlaminar shear stress. The validation of the used model was done with the comparison of the stiffness reduction as a function of crack density and the experimental data. A comparison showed that a satisfactory qualitative and quantitative agreement was obtained. The temperature and moisture concentration variation are studied using the linear and non-linear distribution around the cracks to predict the stress distributions along the axis x. Finally, it observed through this study that the variations of the thermal and moisture concentration distribution largely impact the stress distribution for a sandwich plate with transverse cracks in the central layer and also with different mechanical properties of each layers.

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Non-linear deflection and stress analysis of laminated composite sandwich plate with elliptical cutout under different transverse loadings in hygro-thermal environment

Curved and Layered Structures ◽

10.1515/cls-2020-0008 ◽

2020 ◽

Vol 7 (1) ◽

pp. 80-100

Author(s):

Rahul Kumar ◽

Achchhe Lal ◽

B. M. Sutaria

Keyword(s):

Stress Concentration ◽

Sandwich Plate ◽

Thermal Environment ◽

Shear Deformation Theory ◽

Laminated Composite ◽

Gauss Point ◽

Composite Sandwich ◽

Aspect Ratios ◽

Present Solution ◽

Non Linear

AbstractIn this paper, non-linear transverse deflection, stress and stress concentration factors (SCF) of isotropic and laminated composite sandwich plate (LCSP) with and without elliptical cutouts subjected to various trans-verse loadings in hygrothermal environment are studied. The basic formulation is based on secant function-based shear deformation theory (SFSDT) with von-Karman nonlinearity. The governing equation of non-linear deflection is derived using C0 finite element method (FEM) through minimum potential energy approach. Normalized trans-verse maximum deflections (NTMD) along with stress concentration factor is determined by using Newton’s Raphson method through Gauss point stress extrapolation. Influence of fiber orientations, load parameters, fiber volume fractions, plate span to thickness ratios, aspect ratios, thickness of core and face, position of core, boundary conditions, environmental conditions and types of transverse loading in MATLAB R2015a environment are examined. The numerical results using present solution methodology are verified with the results available in the literatures.

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Vehicle’s New Anti-Roll System for Suspension Parasitic Stiffness Reduction and Non-Linear Roll Stiffness Characteristic

Volume 13: Transportation Systems ◽

10.1115/imece2013-63392 ◽

2013 ◽

Author(s):

Bo Min Kim ◽

Dae Sik Ko ◽

Jong Min Kim

Keyword(s):

Ride Comfort ◽

Torsional Stiffness ◽

Operating Efficiency ◽

Leaf Spring ◽

Roll Motion ◽

Stiffness Reduction ◽

Stiffness Characteristic ◽

Non Linear ◽

Roll System ◽

Vehicle Dynamic Simulation

In general, vehicle uses torsional stiffness of a stabilizer bar to control the roll motion. But this stabilizer bar system has problems with degradation for ride comfort and vehicle’s NVH characteristic due to the suspension parasitic stiffness caused by deformation and wear of the stabilizer bar rubber bush. In addition, it is difficult to control the vehicle’s roll motion effectively in case of excessive vehicle roll behavior when it is designed to satisfy ride comfort simultaneously because of the stabilizer bar’s linear roll stiffness characteristic. In this paper, the new anti-roll system is suggested which consists of connecting link, push rod, laminated leaf spring, and rotational bearing. This new concept anti-roll system can minimize the suspension parasitic stiffness by using rotational bearing structure and give the vehicle non-linear roll stiffness by using the laminated leaf spring structure which are composed of main spring and auxiliary one. Reduction of suspension parasitic stiffness and realization of non-linear roll stiffness in this anti-roll system were verified with both vehicle dynamic simulation and vehicle test. Also, this study includes improvement of the system operating efficiency through material change and shape optimization of the leaf spring, and optimal configuration of the force transfer system.

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A Damage Model Containing Delamination in Composite Laminates

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.324-325.43 ◽

2006 ◽

Vol 324-325 ◽

pp. 43-46

Author(s):

Yu Pu Ma ◽

Xin Zhi Lin ◽

Qing Fen Li ◽

Zhen Li

Keyword(s):

Composite Laminates ◽

Damage Model ◽

Laminated Composite ◽

Shear Lag ◽

Analysis Model ◽

Transverse Cracks ◽

Transverse Cracking ◽

Stiffness Reduction ◽

Laminated Composite Materials ◽

Modulus Reduction

When stress is high, delaminate damage can be induced by transverse cracks. A complete parabolic shear-lag damage model containing delamination induced by transverse cracks is therefore proposed and applied to predict the stiffness reduction by transverse cracking in cross-ply laminated composite materials. The predictions of the complete parabolic shear-lag analysis model, the incomplete parabolic shear-lag analysis model, and the complete parabolic shear-lag damage model containing delamination proposed in this paper have been compared. Results show that the young’s modulus reduction values obtained by our analysis model are better agreement with the experimental ones than other models.

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