Shape Memory Polymer With Aluminum Tube Reinforced Impact Resistant Sandwich Core

2012 ◽  
Author(s):  
Gefu Ji ◽  
Guoqiang Li ◽  
Su-Seng Pang
Keyword(s):  
Shape Memory ◽  
Structural Integrity ◽  
Safety Concern ◽  
Shape Memory Polymer ◽  
Sandwich Panels ◽  
Low Velocity ◽  
The Core ◽  
Sandwich Construction ◽  
Structural Applications ◽  
Sandwich Core

Sandwich construction has been extensively used in various fields. However, sandwich panels have not been fully exploited in critical structural applications due to damage tolerance and safety concern. A major problem of sandwich panels is the debonding at or near the core/face sheet interface, especially under impact loading, which can lead to a sudden loss of structural integrity and cause catastrophic consequences. In order to improve the debonding resistance and energy absorption of sandwich panel under impact loadings, a new sandwich core is proposed which is a hybrid core consisting of hollow metallic millitubes reinforced Shape Memory Polymer matrix. The objective of this study was to characterize its dynamic performances. The core consisted of programmed shape memory polymer resin. Low velocity (4m/s) impact tests demonstrated that new core panel may be considered a promising option for critical structural applications featured by debonding and multiple impact tolerance.

Novel Impact/Debonding Tolerant Sandwich Panel With Millitubes Grid Stiffened Foam Core

2012 ◽  
Author(s):  
Guoqiang Li ◽  
Gefu Ji ◽  
Su-Seng Pang
Keyword(s):  
Sandwich Panel ◽  
Structural Integrity ◽  
Safety Concern ◽  
Sandwich Panels ◽  
Low Velocity Impact ◽  
Foam Core ◽  
Low Velocity ◽  
The Core ◽  
Sandwich Construction ◽  
Structural Applications

Sandwich construction has been extensively used in various fields. However, sandwich panels have not been fully exploited in critical structural applications due to damage tolerance and safety concern. A major problem of sandwich panels is the debonding at or near the core/face sheet interface, especially under impact loading, which can lead to a sudden loss of structural integrity and cause catastrophic consequences. In order to improve the debonding resistance and energy absorption of sandwich panel under impact loadings, a new foam core is proposed which is a hybrid core consisting of grid stiffened hollow metallic millitubes reinforced polymer matrix. The objective of this study was to characterize its dynamic performances. The core consisted of polymer resin reinforced by grid stiffened continuous metallic millitubes. Low velocity impact test demonstrated that new core panel may be considered a promising option for critical structural applications featured by debonding and multiple impact tolerance.

Modeling of Metallic Sandwich Structures

2003 ◽  
Author(s):  
Zhenyu Xue
Keyword(s):  
Constitutive Model ◽  
Blast Resistance ◽  
Constitutive Models ◽  
Complex Structures ◽  
Plate Structures ◽  
The Core ◽  
Sandwich Construction ◽  
Alternative Means ◽  
Anisotropic Elastic ◽  
Sandwich Core

All-metal sandwich construction holds promise for significant improvements in stiffness, strength and blast resistance for built-up plate structures. Analysis of the performance of sandwich plates under various loads, static and dynamic, requires modeling of face sheets and core with some fidelity. While it is possible to model full geometric details of the core for a few selected problems, this is unrealistic for larger complex structures under general loadings. A constitutive model can be proposed as an alternative means of modeling the sandwich core. The constitutive model falls within the framework of a compressible rate-independent, anisotropic elastic-plastic solid. In this paper, the model will be presented in details, along with numerical implementation in a finite element code, and benchmarks its performance against existing constitutive models.

scholarly journals The low-velocity impact and compression after impact (CAI) behavior of foam core sandwich panels with shape memory alloy hybrid face-sheets

2019 ◽  
Vol 26 (1) ◽  
pp. 517-530 ◽  
Author(s):  
Ye Wu ◽  
Yun Wan
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Sandwich Panels ◽  
Image Correlation ◽  
Low Velocity Impact ◽  
Foam Core ◽  
Low Velocity ◽  
Velocity Impact ◽  
Compression After Impact ◽  
The Impact

AbstractDue to the properties of shape memory effect and super-elasticity, shape memory alloy (SMA) is added into glass fiber reinforced polymer (GFRP) face-sheets of foam core sandwich panels to improve the impact resistence performance by many researchers. This paper tries to discuss the failure mechanism of sandwich panels with GF/ epoxy face-sheets embedded with SMA wires and conventional 304 SS wire nets under low-velocity impact and compression after impact (CAI) tests. The histories of contact force, absorbed energy and deflection during the impact process are obtained by experiment. Besides, the failure modes of sandwich panels with different ply modes are compared by visual inspection and scanning electron microscopy (SEM). CAI tests are conducted with the help of digital image correlation (DIC) technology. Based on the results, the sandwich panels embedded with SMA wires can absorb more impact energy, and show relatively excellent CAI performance. This is because the SMA wires can absorb and transmit the energy to the outer region of GFRP face-sheet due to the super-elasticity-behavior. The failure process and mechanism of the CAI test is also discussed.

Impact/Debonding Tolerant Sandwich Panel With Aluminum Tube Reinforced Foam Core

2011 ◽  
Author(s):  
Gefu Ji ◽  
Zhenyu Ouyang ◽  
Guoqiang Li ◽  
Su-Seng Pang
Keyword(s):  
Sandwich Panel ◽  
Load Capacity ◽  
Sandwich Panels ◽  
Interface Debonding ◽  
Type I ◽  
Foam Core ◽  
Type Ii ◽  
Polymer Resin ◽  
The Core ◽  
Structural Applications

Sandwich construction has been extensively used in various fields. However, sandwich panels have not been fully exploited in critical structural applications due to damage tolerance and safety concern. A major problem of sandwich panels is the debonding at or near the core/face sheet interface, especially under impact loading, which can lead to a sudden loss of structural integrity and cause catastrophic consequences. In order to improve the debonding resistance and energy absorption of sandwich panel under impact loadings, a new foam core is proposed which is a hybrid core consisting of hollow metallic microtubes reinforced polymer matrix. The objective of this study was to characterize its static and dynamic performances. Two types of new hybrid cores were investigated in this work. One consisted of polymer resin reinforced by transversely aligned continuous metallic militubes, denoted as type-I sandwich panel. The other was made of polymer resin reinforced by aligned continuous in-plane metallic militubes, denoted as type-II sandwich panel. Additionally, the traditional sandwich panels with polymeric syntactic foam core were also prepared for comparisons. Static and impact tests demonstrated that interface debonding and subsequent shear failure in the core could be largely excluded from the type-II panel. Meanwhile, a significant transition to ductile failure was observed in type-II sandwich panel with dramatically enhanced load capacity and impact energy dissipation. The results indicated that type-II panel may be considered a promising option for critical structural applications featured by debonding and impact tolerance.

Sandwich Core Cracks Approaching the Interface Between the Core and Face Sheets

2007 ◽  
Author(s):  
J. H. Andreasen
Keyword(s):  
Maximum Stress ◽  
Object Oriented Programming ◽  
Programming Environment ◽  
Pure Bending ◽  
The Core ◽  
Sandwich Construction ◽  
Crack Tips ◽  
Maximum Stress Intensity ◽  
Sandwich Core

Cracks approaching the interfaces in the core of a sandwich construction are investigated. For pure tension, pure bending and shear the cracks are shown to go through a regime where a maximum stress intensity factor is attained before the crack tips enter the interface. The cracks are analyzed within the framework of analytical elasticity. The analysis methods are outlined, and the solution is established in an object oriented programming environment, which allows solutions to be obtained for a wide variety of parameters. Results are given in terms of a case study pertaining to sandwich constructions with aluminum faces and two different foamed PVC core, as well as in more generalized terms.

Experimental investigation of sandwich panels with hybrid composite face sheets and embedded shape memory alloy wires under low velocity impact

2020 ◽  
Vol 41 (11) ◽  
pp. 4811-4829
Author(s):  
Seyed A. Masoudi Moghaddam ◽  
Mehdi Yarmohammad Tooski ◽  
Mohsen Jabbari ◽  
Ahmad R. Khorshidvand
Keyword(s):  
Experimental Investigation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Hybrid Composite ◽  
Sandwich Panels ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Composite Face

A Comparative Analysis of Orientation on the Shape Memory Effect of Fabric Reinforced Shape Memory Polymer Composites

2015 ◽  
Vol 830-831 ◽  
pp. 529-532 ◽  
Author(s):  
D. Mohanakrishnan ◽  
M. Sureshkumar
Keyword(s):  
Comparative Analysis ◽  
Shape Memory ◽  
Polymer Composites ◽  
Smart Materials ◽  
Memory Performance ◽  
Shape Memory Polymer ◽  
Matrix Material ◽  
Resin Matrix ◽  
Structural Applications ◽  
Stimulus Temperature

Shape memory polymer composites (SMPC) are a new kind of smart materials where many researches have been carried out. In SMPC, shape memory polymers serves as a matrix material and particles or fibers act as reinforcements. As structural applications demand structures to withstand load and stiffness, particles reinforced SMPC does not serve for it. Therefore fiber/fabric reinforced SMPC used widely for such applications. SMPC’S changes its shape during a typical thermo-mechanical cycle and retracts to its original shape upon external stimulus (temperature). Molecular mechanism is the driving force of these SMP’s. SMP consists of 1.molecular switches and 2. netpoints. This project deals with Epoxy shape memory resin (Matrix material) and fabrics such as Glass, Kevlar and Carbon (Reinforcements).A Comparative analysis was carried out to find which combination gives the best results by bend test. Different orientations were tried for bidirectional fabrics such as (0/90)3, (0/45)3, ((0/90)/(±45)/(0/90)) specimens. Finally it was concluded that Carbon fabric which has the orientation of (0/90/±45/0/90) gives better shape memory performance.

scholarly journals Fused Filament Fabrication-4D-Printed Shape Memory Polymers: A Review

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 701
Author(s):  
Sara Valvez ◽  
Paulo N. B. Reis ◽  
Luca Susmel ◽  
Filippo Berto
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Shape Memory ◽  
Structural Integrity ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Layer By Layer ◽  
4D Printing ◽  
Fused Filament Fabrication ◽  
External Stimuli

Additive manufacturing (AM) is the process through which components/structures are produced layer-by-layer. In this context, 4D printing combines 3D printing with time so that this combination results in additively manufactured components that respond to external stimuli and, consequently, change their shape/volume or modify their mechanical properties. Therefore, 4D printing uses shape-memory materials that react to external stimuli such as pH, humidity, and temperature. Among the possible materials with shape memory effect (SME), the most suitable for additive manufacturing are shape memory polymers (SMPs). However, due to their weaknesses, shape memory polymer compounds (SMPCs) prove to be an effective alternative. On the other hand, out of all the additive manufacturing techniques, the most widely used is fused filament fabrication (FFF). In this context, the present paper aims to critically review all studies related to the mechanical properties of 4D-FFF materials. The paper provides an update state of the art showing the potential of 4D-FFF printing for different engineering applications, maintaining the focus on the structural integrity of the final structure/component.

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