Strain rate and temperature effects of polymer foam core material

2013 ◽  
Vol 16 (1) ◽  
pp. 66-87 ◽  
Author(s):  
Deborah A Williams ◽  
Roberto A Lopez-Anido
Keyword(s):  
Strain Rate ◽  
Temperature Effects ◽  
Core Material ◽  
Foam Core ◽  
Polymer Foam

Impact Response of Sacrificial Cladding Structure with an Alporas Aluminum Foam Core Under Blast Loading

2020 ◽  
Vol 12 (08) ◽  
pp. 2050094
Author(s):  
Ibrahim Elnasri ◽  
Han Zhao
Keyword(s):  
Strain Rate ◽  
Aluminum Foam ◽  
Blast Loading ◽  
Front Propagation ◽  
Analytical Models ◽  
Core Material ◽  
Foam Core ◽  
Arbitrary Lagrangian Eulerian ◽  
Inertia Effects ◽  
Ale Methods

This paper presents numerical and analytical studies of the response of a sacrificial cladding structure with an Alporas aluminum foam core and a thick mild steel cover and rear plates under blast loading. A suitable numerical model in LS-DYNA based on the coupled Load Blast Enhanced/Multi-Material Arbitrary Lagrangian–Eulerian (LBE/MM-ALE) methods is selected and validated using the experimental data available in the literature. The shock front propagation and micro-inertia effects are responsible for the strength enhancement predicted in the virtual blast test. Two models with different decaying blast loading functions are examined to study the fluid–structure interaction (FSI) effect. The simulation results show that the FSI effect is negligible if the foam core is strain-rate insensitive. Further investigations should be conducted with analytical models if the core material of the sacrificial cladding structures exhibits a strong strain-rate effect (for example, Alporas foam).

scholarly journals Experimental Analysis of Perimeter Shear Strength of Composite Sandwich Structures

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 12
Author(s):  
Łukasz Święch ◽  
Radosław Kołodziejczyk ◽  
Natalia Stącel
Keyword(s):  
Experimental Analysis ◽  
Sandwich Structures ◽  
Maximum Load ◽  
Core Material ◽  
Foam Core ◽  
Honeycomb Core ◽  
Loading Test ◽  
Composite Sandwich ◽  
Destruction Mechanism ◽  
Static Loading Test

The work concerns the experimental analysis of the process of destruction of sandwich structures as a result of circumferential shearing. The aim of the research was to determine the differences that occur in the destruction mechanism of such structures depending on the thickness and material of the core used. Specimens with a Rohacell foam core and a honeycomb core were made for the purposes of the research. The specimen destruction process was carried out in a static loading test with the use of a system introducing circumferential shear stress. The analysis of the tests results was made based on the load-displacement curves, the maximum load, and the energy absorbed by individual specimens. The tests indicated significant differences in the destruction mechanism of specimens with varied core material. The specimen with the honeycomb core was characterized by greater stiffness, which caused the damage to occur locally in the area subjected to the pressure of the punch. In specimens with the foam core, due to the lower stiffness of that core, the skins of the structure were bent, which additionally transfers compressive and tensile loads. This led to a higher maximum force that the specimens obtained at the time of destruction and greater energy absorption.

Design of composite lattice materials combined with fabrication approaches

2018 ◽  
Vol 53 (3) ◽  
pp. 393-404 ◽  
Author(s):  
Jun Xu ◽  
Yaobo Wu ◽  
Xiang Gao ◽  
Huaping Wu ◽  
Steven Nutt ◽  
...  
Keyword(s):  
Shear Strength ◽  
Mechanical Performance ◽  
Analytical Models ◽  
Core Material ◽  
Foam Core ◽  
Hierarchical Lattice ◽  
Bottom Up ◽  
Lattice Materials ◽  
Assembly Technique ◽  
Composite Lattice

Lattice materials can be designed through their microstructure while concurrently considering fabrication feasibility. Here, we propose two types of composite lattice materials with enhanced resistance to buckling: (a) hollow lattice materials fabricated by a newly developed bottom-up assembly technique and the previously developed thermal expansion molding technique and (b) hierarchical lattice materials with foam core sandwich trusses fabricated by interlocking assembly process. The mechanical performance of sandwich structures featuring the two types of lattice cores was tested and analyzed theoretically. For hollow lattice core material, samples from two different fabrication processes were compared and both failed by nodal rupture or debonding. In contrast, hierarchical lattice structures failed by shear buckling without interfacial failure in the sandwich struts. Calculations using established analytical models indicated that the shear strength of hollow lattice cores could be optimized by judicious selection of the thickness of patterned plates. Likewise, the shear strength of hierarchical foam core truss cores could be maximized (with minimal weight) through design of truss geometry. The bottom-up assembly technique could provide a feasible way for mass production of lattice cores, but the design about how to assembly is critical. Hierarchical lattice cores with foam sandwich trusses should be a suitable choice for future lightweight material application.

scholarly journals Strain rate and temperature effects on the selection of primary and secondary slip and twinning systems in HCP Zr

2015 ◽  
Vol 88 ◽  
pp. 55-73 ◽  
Author(s):  
Marko Knezevic ◽  
Milovan Zecevic ◽  
Irene J. Beyerlein ◽  
John F. Bingert ◽  
Rodney J. McCabe
Keyword(s):  
Strain Rate ◽  
Temperature Effects ◽  
Secondary Slip ◽  
Selection Of

scholarly journals Polymer Foam Core Aluminum Sandwich Lightweight Car Hood for Pedestrian Protection

2018 ◽  
Vol 134 (1) ◽  
pp. 231-234
Author(s):  
Y. Can ◽  
M. Yazıcı ◽  
H. Güçlü
Keyword(s):  
Foam Core ◽  
Pedestrian Protection ◽  
Polymer Foam

Creep Responses of Smart Sandwich Composites at Multiple Length Scales: Experiments and Modeling

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Anaïs Farrugia ◽  
Charles Winkelmann ◽  
Valeria La Saponara ◽  
Jeong Sik Kim ◽  
Anastasia H. Muliana
Keyword(s):  
Creep Behavior ◽  
Composite Structures ◽  
Effective Properties ◽  
Micromechanical Model ◽  
Foam Core ◽  
Sandwich Beams ◽  
Fiber Reinforced ◽  
Polymer Foam ◽  
Creep Tests ◽  
Unique Challenge

In service, composite structures present the unique challenge of damage detection and repair. Piezoelectric ceramic, such as lead zirconate titanate (PZT), is often used for detecting damage in composites. This paper investigates the effect of embedded PZT crystals on the overall creep behavior of sandwich beams comprising of glass fiber reinforced polymer laminated skins and polymer foam core, which could potentially be used as a damage-detecting smart structure. Uniaxial quasi-static and creep tests were performed on the glass/epoxy laminated composites having several fiber orientations, 0 deg, 45 deg, and 90 deg, to calibrate the elastic and viscoelastic properties of the fibers and matrix. Three-point bending creep tests at elevated temperature (80°C) were then carried out for a number of control sandwich beams (no PZT crystal) and conditioned sandwich beams (with PZT crystals embedded in the center of one facesheet). Lateral deflection of the sandwich beams was monitored for more than 60 h. The model presented in this paper is composed by two parts: (a) a simplified micromechanical model of unidirectional fiber reinforced composites used to obtain effective properties and overall creep response of the laminated skins and (b) a finite element method to simulate the overall creep behavior of the sandwich beams with embedded PZT crystals. The simplified micromechanical model is implemented in the material integration points within the laminated skin elements. Fibers are modeled as linear elastic, while a linearized viscoelastic material model is used for the epoxy matrix and foam core. Numerical results on the creep deflection of the smart sandwich beams show good correlations with the experimental creep deflection at 80°C, thus proving that this model, although currently based on material properties reported at room temperature, is promising to obtain a reasonable prediction for the creep of a smart sandwich structure at high temperatures.

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.

Sign in / Sign up

Export Citation Format

Share Document