Measurement of Material Properties for Metal Foam Cored Polymer Composite Sandwich Construction

2004 ◽  
Vol 1-2 ◽  
pp. 211-216 ◽  
Author(s):  
S. McKown ◽  
Robert A.W. Mines
Keyword(s):  
Polymer Composite ◽  
Material Properties ◽  
Large Scale ◽  
Metal Foam ◽  
Progressive Collapse ◽  
Material Model ◽  
Sandwich Beams ◽  
Composite Sandwich ◽  
Compression Data ◽  
The Impact

Material properties are required for the numerical simulation of the impact progressive collapse of metal foam cored polymer composite sandwich beams, using LS-DYNA. As far as the metal foam, Alporas, is concerned, multi-axial tension and compression data is required. This includes large scale crush and tensile rupture. An Arcan test fixture was developed, in which a sample of foam can be subject to tensile and shear deformation simultaneously. The data was also used to calibrate the crushable foam material model in LS-DYNA. For the skin, tensile and compression data was generated for a cross ply glass fibre thermoplastic laminate. The data was then used to calibrate the composite damage material model in LS-DYNA. Inclusion of calibrated material models into the simulation of the progressive collapse of metal foam cored composite sandwich beams will be briefly discussed.

An Introduction to the Impact Behaviour of Polymer Composites Using Simplified Beam Models

1998 ◽  
Vol 26 (2) ◽  
pp. 89-110 ◽  
Author(s):  
R. A. W. Mines
Keyword(s):  
Composite Materials ◽  
Undergraduate Students ◽  
Progressive Collapse ◽  
Structural Response ◽  
Sandwich Beams ◽  
Three Point Bending ◽  
The Past ◽  
Structural Case ◽  
The University ◽  
The Impact

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.

Rate Dependent Material Model for Helmet Pads

2020 ◽  
Author(s):  
Timothy G. Zhang ◽  
A. H. Fulton ◽  
K. Ravi-Chandar ◽  
Sikhanda S. Satapathy
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
High Speed ◽  
Material Model ◽  
High Speed Camera ◽  
Low Velocity ◽  
Rate Dependent ◽  
Military Helmet ◽  
The Impact ◽  
Impact Experiments

Abstract Foam pads are commonly used in sports and military helmet for energy absorption, form-fitting and comfort. Both for low velocity and high velocity applications, their rate-dependent mechanical properties need to be characterized to understand their ability to effectively modulate the transmitted stress pulse. Impact experiments were conducted on bilayer helmet pads at a range of velocities covering low to medium rates up to ∼7000/s. Images from high-speed camera were used to construct x-T diagrams to measure the shock speeds from the impact experiments. Numerical simulations were carried out to validate a foam pad model and to understand experimental uncertainties. The scatter in the measured shock speeds was found to be related to the scatter in the material properties.

Vibration behavior of visco-elastically coupled sandwich beams with magnetorheological core and three-phase carbon nanotubes/fiber/polymer composite facesheets subjected to external magnetic field

2017 ◽  
Vol 21 (7) ◽  
pp. 2194-2218 ◽  
Author(s):  
A Ghorbanpour Arani ◽  
H BabaAkbar Zarei ◽  
M Eskandari ◽  
P Pourmousa
Keyword(s):  
Magnetic Field ◽  
Carbon Nanotubes ◽  
Polymer Composite ◽  
Field Intensity ◽  
Material Properties ◽  
Vibration Analysis ◽  
Magnetic Field Intensity ◽  
Thickness Ratio ◽  
Winkler Foundation ◽  
Sandwich Beams

In the present research, modeling and vibration analysis of the double of sandwich beams which are coupled by visco-Pasternak medium are investigated. Also, this system is rested on Winkler foundation. Sandwich beams consist of magnetorheological core and carbon nanotubes/fiber/polymer composite facesheets. The material properties of magnetorheological core are obtained using the experimental data available in literature. Halpin–Tsai model is utilized to determine the material properties of carbon nanotubes/fiber/polymer composite facesheets. Hamilton principle is used to obtain the equations of motion of this system. Based on Navier’s method, a closed-form solution is presented for free vibration analysis of coupled magnetorheological sandwich beams under simply supported boundary conditions. The effects of various parameters such as core-to-facesheets thickness ratio, length-to-thickness ratio, magnetic field intensity, volume fractions of carbon nanotubes, and fibers and visco-Pasternak coefficients on the natural frequencies and loss factors of coupled system are discussed. The results show that the modal loss factor, unlike natural frequency, decreases by increasing magnetic field intensity. These findings can be used in design and manufacturing of sandwich structures.

Static Behaviour of Pre-stressed Polymer Composite Sandwich Beams

2006 ◽  
pp. 671-682 ◽  
Author(s):  
R. A. W. Mines ◽  
Q. M. Li ◽  
R. S. Birch ◽  
R. Rigby ◽  
M. Al-Khalil ◽  
...  
Keyword(s):  
Polymer Composite ◽  
Sandwich Beams ◽  
Composite Sandwich ◽  
Stressed Polymer ◽  
Static Behaviour

OPTIMAL DESIGN OF SANDWICH BEAMS WITH LIGHTWEIGHT CORES IN THREE-POINT BENDING

2012 ◽  
Vol 04 (03) ◽  
pp. 1250033 ◽  
Author(s):  
LI-MING CHEN ◽  
MING-JI CHEN ◽  
YONG-MAO PEI ◽  
YI-HUI ZHANG ◽  
DAI-NING FANG
Keyword(s):  
Metal Foam ◽  
Minimum Weight ◽  
Weight Ratio ◽  
Optimization Process ◽  
Stiffness Index ◽  
Sandwich Beams ◽  
Bending Performance ◽  
Three Point Bending ◽  
Composite Sandwich ◽  
Mode Of Failure

Being widely used in engineering, the optimization of sandwich beams to achieve greater stiffness-to-weight ratio is of great research interest. In this paper, the optimization process was carried to obtain minimum weight designs in three-point bending based on prescribed stiffness index. Results indicate that honeycomb-cored sandwich beams possess smaller minimum weight index in comparison with metal foam-cored beams. In addition, failure mechanisms of the optimized designs were also investigated to reveal that the sandwich-cored beams were more prone to face wrinkling than metal foam-cored beams. In the optimization process, five different core topologies and four different parent materials were investigated under a given load index. It was found for low prescribed load values where bending is dominant, unidirectional lattice composite sandwich beams bear loads more efficiently than steel cored beams. However, the primary mode of failure for high prescribed load index is core shear, thus implying no significant advantage in lattice composite sandwich beams over other materials. Comparing the different materials, that laminate lattice composite sandwich beams possess the best bending performance for varying levels of prescribed load index, making it suitable for applications in the aerospace field.

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