Comparative Analysis of Crashworthiness Capability of Laminate Tubes Structure with 0° Plies of Unidirectinally Arrayed Chopped Strand

2017 ◽  
Vol 744 ◽  
pp. 305-310
Author(s):  
Abdullah Atiq Ariffin ◽  
Wen Xue Wang ◽  
Terutake Matsubara

This paper presents the crashworthiness performance of carbon reinforced epoxy laminate tubular structure of three different kind tubes made of 0˚ plies Unidirectionally Arrayed Chopped Strand (UACS) introduced into laminate tube. UACS plies with discontinuous angled slit and slit perpendicular to fiber direction, namely bi-angle slits and staggered slits were used as 0˚ ply, respectively, instead of conventional continuous fiber ply to investigate relationship between crashworthiness capacities and progressive collapse behavior under quasi-static crushing tests. Newly designed laminate tube for crashworthy structure made of 0˚ plies UACS bi-angle slits and staggered slit was succesfully enhanced specific energy absorption by about 9.1% and 4.3% respectively compare to conventional continuous fiber laminate tube. The crushed laminate tubes then were sectioned through the impact point and micro-photograph were taken to show the failure behavior, which include effect of distribution slit on delamination, matrix cracking, curvature size, friction, etc. It is shown that UACS laminate beside of showing excellent formability also become newly auto trigger mechanism to achieve much stable and controllable collapse with much extensive fiber fracture occurred.

2013 ◽  
Vol 650 ◽  
pp. 298-303
Author(s):  
Ying Xu ◽  
Wei Dong Wen ◽  
Yu Huo

Aimed at the lack of research about damage mechanism, a 3-D progressive impact damage analysis method was applied to analyze the low-energy impact damage process of T300/BMP-316 laminates with three different ply stacking sequences. The influences of ply parameters on the impact damage of laminates were researched. The impact damage mechanism was analyzed combined with the figure of impact stress in laminates. It is showed that the matrix cracking is caused by the inconsistent distortion of the matrix and fiber when the tensile stress that perpendicular to the fiber direction reaches a given value, and the delamination near to the impacted back face and front face are caused individually by the matrix cracking and the inconsistent bend stiffness between two laminas.


1988 ◽  
Vol 110 (2) ◽  
pp. 128-133 ◽  
Author(s):  
C. E. Harris ◽  
D. H. Allen ◽  
E. W. Nottorf ◽  
S. E. Groves

Continuous fiber laminated composites are known to undergo substantial load induced damage in the form of matrix cracking, interior delamination, fiber fracture, etc. These damage modes produce significant losses in component performance measures such as stiffness, residual strength, and life. The authors have previously constructed a general model for predicting the response of laminated composites with damage. The current paper utilizes the model to predict stiffness loss as a function of damage in quasi-isotropic and angle-ply laminates with matrix cracks. It is shown that the model is capable of predicting the stiffness loss for any layup by utilizing the same input data, thus producing a model which is independent of stacking sequence. The favorable comparisons of the model to experimental results reported herein support the validity of the model.


2021 ◽  
Vol 60 (1) ◽  
pp. 145-157
Author(s):  
Yi Luo ◽  
Ke Yuan ◽  
Lumin Shen ◽  
Jiefu Liu

Abstract In this study, a series of in-plane hexagonal honeycombs with different Poisson's ratio induced by topological diversity are studied, considering re-entrant, semi-re-entrant and convex cells, respectively. The crushing strength of honeycomb in terms of Poisson's ratio is firstly presented. In the previous research, we have studied the compression performance of honeycomb with different negative Poisson's ratio. In this study, a comparative study on the local impact resistance of different sandwich panels is conducted by considering a spherical projectile with low to medium impact speed. Some critical criteria (i.e. local indentation profile, global deflection, impact force and energy absorption) are adopted to analyze the impact resistance. Finally, an influential mechanism of Poisson's ratio on the local impact resistance of sandwich panel is studied by considering the variation of core strength and post-impact collapse behavior.


2012 ◽  
Vol 27 (2) ◽  
pp. 318-328 ◽  
Author(s):  
Svetlana Borodulina ◽  
Artem Kulachenko ◽  
Mikael Nygårds ◽  
Sylvain Galland

Abstract We have investigated a relation between micromechanical processes and the stress-strain curve of a dry fiber network during tensile loading. By using a detailed particle-level simulation tool we investigate, among other things, the impact of “non-traditional” bonding parameters, such as compliance of bonding regions, work of separation and the actual number of effective bonds. This is probably the first three-dimensional model which is capable of simulating the fracture process of paper accounting for nonlinearities at the fiber level and bond failures. The failure behavior of the network considered in the study could be changed significantly by relatively small changes in bond strength, as compared to the scatter in bonding data found in the literature. We have identified that compliance of the bonding regions has a significant impact on network strength. By comparing networks with weak and strong bonds, we concluded that large local strains are the precursors of bond failures and not the other way around.


1998 ◽  
Vol 26 (2) ◽  
pp. 89-110 ◽  
Author(s):  
R. A. W. Mines

The paper describes a final-year undergraduate course that has been taught at the University of Liverpool for the past three years. The main aims of the course are to introduce the student to the design of structures using multi-component (composite) materials and to the performance of such structures under impact loading. Given the complexity of generalized composite behaviour and of structural crashworthiness, a simple structural case is considered, namely, a beam subject to three-point bending. A feature of the course is that not only is linear structural response considered but also non-linear (progressive) structural collapse is covered. The course is split into four parts, namely: (i) analysis of composite laminae, (ii) analysis of laminated beams, (iii) local and global effects in sandwich beams, and (iv) post-failure and progressive collapse of sandwich beams. Static and impact loadings are considered. Comments are made on how the theories are simplified and communicated to the undergraduate students.


Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3426 ◽  
Author(s):  
Eugenio Marino-Merlo ◽  
Andrea Bulletti ◽  
Pietro Giannelli ◽  
Marco Calzolai ◽  
Lorenzo Capineri

The structural health monitoring (SHM) of critical structures is a complex task that involves the use of different sensors that are also aimed at the identification of the location of the impact point using ultrasonic sensors. For the evaluation of the impact position, reference is often made to the well-known triangulation method. This method requires the estimation of the differential time of arrival (DToA) and the group velocity of the Lamb waves propagating into a plate-like structure: the uncertainty of these two parameters is taken into consideration as main cause of localization error. The work proposes a simple laboratory procedure based on a set-up with a pair of sensors that are symmetrically placed with respect to the impact point, to estimate the uncertainty of the DToA and the propagation velocity estimates. According to a theoretical analysis of the error for the impact position, the experimental uncertainties of DToA and the propagation velocity are used to estimate the overall limit of the SHM system for the impact positioning. Because the error for the DToA estimate depends also on the adopted signal processing, three common methods are selected and compared: the threshold, the correlation method, and a likelihood algorithm. Finally, the analysis of the positioning error using multisensory configuration is reported as useful for the design of the SHM system.


1993 ◽  
Vol 115 (1) ◽  
pp. 91-102 ◽  
Author(s):  
A. Chulya ◽  
J. P. Gyekenyesi ◽  
R. T. Bhatt

The mechanical behavior of continuous fiber-reinforced SiC/RBSN composites with various fiber contents is evaluated. Both catastrophic and noncatastrophic failures are observed in tensile specimens. Damage and failure mechanisms are identified via in-situ monitoring using NDE techniques throughout the loading history. Effects of fiber/matrix interface debonding (splitting) parallel to the fibers are discussed. Statistical failure behavior of fibers is also observed, especially when the interface is weak. Micromechanical models incorporating residual stresses to calculate the critical matrix cracking strength, ultimate strength, and work of pull-out are reviewed and used to predict composite response. For selected test problems, experimental measurements are compared to analytic predictions.


2015 ◽  
Vol 665 ◽  
pp. 277-280 ◽  
Author(s):  
Aniello Riccio ◽  
S. Saputo ◽  
A. Sellitto ◽  
A. Raimondo ◽  
R. Ricchiuto

The investigation of fiber-reinforced composite laminates mechanical response under impact loads can be very difficult due to simultaneous failure phenomena. Indeed, as a consequence of low velocity impacts, intra-laminar damage as fiber and matrix cracking and inter-laminar damage, such as delamination, often take place concurrently, leading to significant reductions in terms of strength and stability for composite structure. In this paper a numerical study is proposed which, by means of non-linear explicit FEM analysis, aims to completely characterize the composite reinforced laminates damage under low velocity impacts. The numerical investigation allowed to obtain an exhaustive insight on the different phases of the impact event considering the damage formation and evolution. Five different impact locations with the same impact energy are taken into account to investigate the influence on the onset and growth of damage.


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