scholarly journals Experimental and Numerical Analysis of Nonlinear Flexural Behaviour of Lattice-Web Reinforced Foam Core Composite Sandwich Panels

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jiye Chen ◽  
Hai Fang ◽  
Weiqing Liu ◽  
Yujun Qi ◽  
Lu Zhu
Keyword(s):  
Numerical Analysis ◽  
Carrying Capacity ◽  
Sandwich Panels ◽  
Foam Core ◽  
Load Carrying Capacity ◽  
Flexural Behaviour ◽  
Composite Sandwich Panels ◽  
Composite Sandwich ◽  
Load Carrying ◽  
The Face

This paper conducted experimental and numerical analysis of the nonlinear flexural behaviour of lattice-web reinforced foam core composite sandwich panels. Composite sandwich panels composed of a polyurethane (PU) foam core with glass fibre-reinforced polymer (GFRP) composites as the face sheets and lattice webs were fabricated through the vacuum infusion moulding process (VIMP). The flexural behaviour of these composite sandwich panels were experimentally investigated under both uniformly distributed and concentrated loading scenarios. The results showed that reinforced lattice webs can significantly increase the flexural stiffness and load-carrying capacity of sandwich panels and effectively postpone the onset of interfacial debonding failure between the face sheets and core. The effects of the lattice-web height and spacing on the ductility and load-carrying capacities of the sandwich panels were also analysed. Several numerical simulations on lattice-web reinforced foam core composite sandwich panels under concentrated loadings were also conducted. The effectiveness of the finite element (FE) model was validated by the experimental work. Parametric studies indicated that thicker face sheets and lattice webs can remarkably increase the load-carrying capacity. Moreover, the load-carrying capacity and midspan deflection were hardly affected by the foam density.

Implication of Anisotropy of Face-Sheets and Core Layer Materials on the Load Carrying Capacity of Advanced Sandwich Panels: Linear and Nonlinear Responses

2000 ◽  
Author(s):  
Liviu Librescu
Keyword(s):  
Carrying Capacity ◽  
Sandwich Structure ◽  
Sandwich Panels ◽  
Core Layer ◽  
Anisotropic Materials ◽  
Load Carrying Capacity ◽  
The Core ◽  
Load Carrying ◽  
The Face ◽  
Sandwich Shells

Abstract This paper deals with a comprehensive geometrically nonlinear theory of shallow sandwich shells that includes also the effect of the initial geometric imperfections. It is assumed that the face-sheets of the sandwich structure are built-up from anisotropic materials layers, whereas the core layer from an orthotropic material. As a result of its features the structural model can provide important information related to the load carrying capacity of sandwich structures in the pre- and postbuckling ranges. Moreover, by using the directionality properties of face-sheets materials, possibilities of enhancing the load carrying capacity of sandwich shells/plates are reached. Selected numerical illustrations emphasizing these features are presented and pertinent conclusions on the beneficial implications of anisotropy of face-sheets and core layer materials upon the load-carrying capacity of sandwich panels are emphasized. Under the present study, the sandwich structure consists of a thick core-layer bonded by the face-sheets that consist of composite anisotropic materials, symmetrically laminated with respect to the mid-surface of the core-layer. The initial geometric imperfection consisting of a stress free initial transversal deflection, will be also incorporated in the study. The loads under which the nonlinear response will be analyzed consist basically of uniaxial/biaxial compressive edge and lateral loads.

Investigation of progressive failure in the composite sandwich panels with elastomeric foam core under concentrated loading

2017 ◽  
Vol 21 (8) ◽  
pp. 2585-2615
Author(s):  
AR Nazari ◽  
MZ Kabir ◽  
H Hosseini-Toudeshky ◽  
Y Alizadeh Vaghasloo ◽  
S Najafian
Keyword(s):  
Energy Absorption ◽  
Composite Laminates ◽  
Sandwich Panels ◽  
Absorption Capacity ◽  
Foam Core ◽  
Energy Absorption Capacity ◽  
Composite Sandwich Panels ◽  
Composite Sandwich ◽  
Load Carrying ◽  
Composite Skins

Failure and damage of crushable materials employed as core for the sandwich structures reduces serviceability and energy absorption capacity of the components especially under bending load so that many beneficial properties seem to be achieved by application of noncrushable lightweight materials instead of crushable foams as core for the sandwich structures. In this paper, an elastomeric foam is employed as core for two aspect ratios of the composite sandwich panels and the enhancement of the load-carrying capacity in the elastomeric foam-cored sandwich panels is investigated in comparison to which is measured about the individual composite panels applied as skins. Both experimental and finite element simulation programs are included in the research. The load-carrying performance of the elastomeric foam-cored sandwich panels is considered dependent on two main features of the constituent materials as hyperelastic behavior of the foam core and progressive damage of the composite skins which are simulated in the finite element models in order to describe the failure mechanism in the panels. Collapse of the elastomeric foam-cored sandwich panels is considered due to connection of some failure lines in the composite skins; however, the foam core remains undamaged. The elastomeric foam core can transfer the load from the top composite skin to the bottom one so that a great energy absorption capacity is provided for these panels. The elastomeric foam after failure of the composite skins can mobilize the residual strength of the laminates to endure against large deformations prior to final collapse. By application of the composite laminates in sandwich form with elastomeric foam core, the maximum load carrying and energy absorption capacity of the composite laminates increased about 60 and 110%, respectively. The results show more favorite failure behavior for the elastomeric foam-cored sandwich panels in comparison to which is expected usually for the crushable foam-cored sandwich panels which may be concerned in many industrial applications.

Investigation of elastomeric foam response applied as core for composite sandwich beams through progressive failure of the beams

2017 ◽  
Vol 21 (2) ◽  
pp. 604-638
Author(s):  
AR Nazari ◽  
MZ Kabir ◽  
H Hosseini Toudeshky
Keyword(s):  
Finite Element ◽  
Carrying Capacity ◽  
Progressive Failure ◽  
Core Material ◽  
Foam Core ◽  
Sandwich Beams ◽  
Load Carrying Capacity ◽  
Composite Sandwich ◽  
The Core ◽  
Load Carrying

In this paper an elastomeric foam is applied as core for the composite sandwich beams and load carrying capacity, load–deflection response, and progressive failure are examined through experimental and finite element studies. The objective of this study is to assess the efficiency of elastomeric foam-cored sandwich (EFCS) beams relative to crushable foam-cored sandwich (CFCS) beams. The experimental program consists of two phases. In the first phase, some characterization tests are conducted on the constituent materials of the sandwich beams such as tension, compression, and shear tests on the foam and bending test on the composite beams utilized as skins. Then in the second phase, the performance of the sandwich beams is examined under bending conditions. The load carrying behavior of the sandwich beams is considered dependent on two main features of the constituent materials: (1) the hyperelastic behavior of the foam core and (2) the progressive damage of the composite skins. These characteristics are simulated by the finite element models. Due to elastomeric rather than crushable deformation of the applied foam as the core, the conventional damage modes of the CFCS beams associated to the brittleness of the core material are omitted through load carrying capacity of the EFCS beams. So in the recent sandwich beams by omission of the core failure modes and utilization of compressive residual strength of the top composite skin, considerable energy is absorbed prior to failure of the bottom composite skin. By simulation of the test specimens using FE models, the response of the foam applied as core for the sandwich beams through progressive failure of the beams is investigated. The results show that the elastomeric foam core can provide superior features for the sandwich components especially for the cases in which high energy absorption capacity is required.

Structural Performance of Fiber-Reinforced Polymer Honeycomb Sandwich Panels: Evaluation of Size Effect and Wrap Strengthening

2003 ◽  
Vol 1845 (1) ◽  
pp. 191-199 ◽  
Author(s):  
Ondrej Kalny ◽  
Robert J. Peterman ◽  
Guillermo Ramirez ◽  
C. S. Cai ◽  
Dave Meggers
Keyword(s):  
Carrying Capacity ◽  
Ultimate Load ◽  
Sandwich Panels ◽  
Fiber Reinforced Polymer ◽  
Load Carrying Capacity ◽  
Flexural Capacity ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Honeycomb Sandwich ◽  
Ultimate Load Carrying Capacity

Stiffness and ultimate load-carrying capacities of glass fiber-reinforced polymer honeycomb sandwich panels used in bridge applications were evaluated. Eleven full-scale panels with cross-section depths ranging from 6 to 31.5 in. (152 to 800 mm) have been tested to date. The effect of width-to-depth ratio on unit stiffness was found to be insignificant for panels with a width-to-depth ratio between 1 and 5. The effect of this ratio on the ultimate flexural capacity is uncertain because of the erratic nature of core-face bond failures. A simple analytical formula for bending and shear stiffness, based on material properties and geometry of transformed sections, was found to predict service-load deflections within 15% accuracy. Although some factors influencing the ultimate load-carrying capacity were clearly identified in this study, a reliable analytical prediction of the ultimate flexural capacity was not attained. This is because failures occur in the bond material between the outer faces and core, and there are significant variations in bond properties at this point due to the wet lay-up process, even for theoretically identical specimens. The use of external wrap layers may be used to shift the ultimate point of failure from the bond (resin) material to the glass fibers. Wrap serves to strengthen the relatively weak core–face interface and is believed to bring more consistency in determining the ultimate load-carrying capacity.

scholarly journals Design of steering system of a buggy

2020 ◽  
Vol 327 ◽  
pp. 03004
Author(s):  
D. Santana Sanchez ◽  
A. Mostafa
Keyword(s):  
Carrying Capacity ◽  
Steering System ◽  
Nonlinear Finite Element ◽  
Load Carrying Capacity ◽  
Dynamic Effects ◽  
Flexural Behaviour ◽  
Steering Angle ◽  
Load Carrying ◽  
And Performance ◽  
Good Agreement

The present paper discusses the design analysis and limitations of the steering system of a buggy. Many geometrical and performance characteristics of the designed steering system were considered to address the kinematic constraints and load carrying capacity of the steering elements. Ackremann geometry approach was used to assess the limiting steering angle, while Lewis bending formula with the inclusion of dynamic effects was employed to characterise the flexural properties of the rack and pinion steering system. Analytical results were numerically verified using ABAQUS/Explicit nonlinear finite element (FE) package. Good agreement has been achieved between analytical and numerical results in predicting the flexural behaviour of the steering rack and pinion system.

Experimental investigations on the sandwich composite beams and panels with elastomeric foam core

2017 ◽  
Vol 21 (3) ◽  
pp. 865-894 ◽  
Author(s):  
AR Nazari ◽  
H Hosseini-Toudeshky ◽  
MZ Kabir
Keyword(s):  
Carrying Capacity ◽  
Sandwich Structures ◽  
Failure Mechanisms ◽  
Composite Beams ◽  
Core Material ◽  
Foam Core ◽  
Sandwich Beams ◽  
Load Carrying Capacity ◽  
The Core ◽  
Load Carrying

In this paper, the load-carrying capacity and failure mechanisms of sandwich beams and panels with elastomeric foam core and composite laminate face sheets are investigated. For this purpose, the flexural behavior of laminated composite beams and panels (applied as face sheets) is firstly investigated under three-point bending and central concentrated loads, respectively. Then, the same examination is conducted for the sandwich beams and panels, in which the proposed elastomeric foam is utilized as the core material. It is shown that the failure mechanisms which are associated to the core in the sandwich structures with crushable foams are not considered in the examined sandwich structures. The collapse of the sandwich specimens, examined here, is observed due to the failure of the skins in some steps. By multi-step collapse of these specimens via separately failure of the top and bottom skins, a considerable amount of energy is absorbed between these steps. Due to non-brittle behavior of the core material under loading, a large compression resistance is observed after failure of the top skin which led to the recovery of the load-carrying capacity in the sandwich beams. A similar behavior for the sandwich panels led to the increase of the ultimate strength after appearance of the failure lines on the top skin. The general outcomes of this investigation promise a good influence for the application of elastomeric foam as core material for sandwich structures.

scholarly journals Load carrying capacity of the eccentric joint in the truss made of open cross-sections

2018 ◽  
Vol 219 ◽  
pp. 02002
Author(s):  
Małgorzata Gordziej-Zagórowska ◽  
Elżbieta Urbańska-Galewska
Keyword(s):  
Numerical Analysis ◽  
Cross Section ◽  
Experimental Research ◽  
Cross Sections ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Main Achievement ◽  
Joint Area ◽  
Load Carrying ◽  
Open Cross Section

The influence of eccentricity at intersections of truss members on the load carrying capacity of the truss joint is presented in the paper. The research truss elements were designed as cold-formed open cross section. Analytical calculations, numerical analysis and experimental research were conducted to reveal how the eccentricity affects the effort of material in the joint area. The results of analysis and investigations are compared and discussed. The main achievement of the tests carried out is statement that slender plane members of the compression chords are safe compared with the results of analytical calculations.

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