Comparison on Compressive Behaviour of Aluminium Honeycomb and Titanium Alloy Micro Lattice Blocks

2011 ◽  
Vol 462-463 ◽  
pp. 213-218 ◽  
Author(s):  
Rafidah Hasan ◽  
Robert A.W. Mines ◽  
Eva Shen ◽  
Sozohn Tsopanos ◽  
Wesley Cantwell
Keyword(s):  
Titanium Alloy ◽  
Compression Strength ◽  
Structural Design ◽  
Lattice Structure ◽  
Experimental Tests ◽  
Core Material ◽  
Aerospace Application ◽  
Compressive Behaviour ◽  
Sandwich Construction

The paper discusses the compressive behaviour of two materials, the conventional aluminium honeycomb and the new titanium alloy micro lattice blocks. The new titanium alloy micro lattice structure is being developed as core material candidate in sandwich construction for aerospace application. Experimental tests have been done on the blocks in order to compare its property with the aluminium honeycomb. Compression strength as well as compressive behaviour of both materials are compared and observed. The mechanisms that contributed to the differences in their performance are discussed and this will be used to improve the geometrical and structural design of micro lattice structure in order to achieve properties that are superior or at least comparable with that of aluminium honeycomb.

Static and dynamic response of sandwich beams with lattice and pantographic cores

2021 ◽  
pp. 109963622110338
Author(s):  
Yury Solyaev ◽  
Arseniy Babaytsev ◽  
Anastasia Ustenko ◽  
Andrey Ripetskiy ◽  
Alexander Volkov
Keyword(s):  
Mechanical Performance ◽  
Lattice Structure ◽  
Unit Length ◽  
Experimental Tests ◽  
Plane Geometry ◽  
Sandwich Beams ◽  
Static Tests ◽  
Three Point Bending ◽  
The Core ◽  
The Impact

Mechanical performance of 3d-printed polyamide sandwich beams with different type of the lattice cores is investigated. Four variants of the beams are considered, which differ in the type of connections between the elements in the lattice structure of the core. We consider the pantographic-type lattices formed by the two families of inclined beams placed with small offset and connected by stiff joints (variant 1), by hinges (variant 2) and made without joints (variant 3). The fourth type of the core has the standard plane geometry formed by the intersected beams lying in the same plane (variant 4). Experimental tests were performed for the localized indentation loading according to the three-point bending scheme with small span-to-thickness ratio. From the experiments we found that the plane geometry of variant 4 has the highest rigidity and the highest load bearing capacity in the static tests. However, other three variants of the pantographic-type cores (1–3) demonstrate the better performance under the impact loading. The impact strength of such structures are in 3.5–5 times higher than those one of variant 4 with almost the same mass per unit length. This result is validated by using numerical simulations and explained by the decrease of the stress concentration and the stress state triaxiality and also by the delocalization effects that arise in the pantographic-type cores.

scholarly journals An Effective Method of Modeling the Deformation Behavior of Polymer Sandwich Structures with Adhesive Joints

2021 ◽  
Author(s):  
László Takács ◽  
Ferenc Szabó
Keyword(s):  
Deformation Behavior ◽  
Sandwich Structures ◽  
Experimental Tests ◽  
Mechanical Tests ◽  
Adhesive Joints ◽  
Core Material ◽  
Full Vehicle ◽  
Novel Approach ◽  
Stiffness Matrices ◽  
Layered Shells

AbstractPolymer sandwich structures have high bending stiffness and strength and also low weight. Therefore, they are widely used in the transportation industry. In the conceptual design phase, it is essential to have a method to model the mechanical behavior of the sandwich and its adhesive joints accurately in full-vehicle scale to investigate different structure partitioning strategies. In this paper, a novel approach using finite element modeling is introduced. The sandwich panels are modeled with layered shells and the joint lines with general stiffness matrices. Stiffness parameters of the face-sheets and the core material are obtained via mechanical tests. Stiffness parameters of the joints are determined by using the method of Design of Experiments, where detailed sub-models of the joints serve as a reference. These models are validated with experimental tests of glass-fiber reinforced vinyl ester matrix composite sandwich structure with a foam core. By using two joint designs and three reference geometries, it is shown that the method is suitable to describe the deformation behavior in a full-vehicle scale with sufficient accuracy.

The Structure and Mechanical Properties of VT23 Welded Joints with Surface Layer Modified by Ultrasonic Mechanical Forging

2017 ◽  
Vol 743 ◽  
pp. 264-268 ◽  
Author(s):  
Anastasia Smirnova ◽  
Yury Pochivalov ◽  
Victor Panin ◽  
Anatoly Orishich ◽  
Aleksandr Malikov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Fatigue Life ◽  
Welded Joints ◽  
Experimental Tests ◽  
Relaxation Property ◽  
Surface Layers ◽  
Β Phase ◽  
Fatigue Life Test ◽  
Vt23 Titanium Alloy

The structure and mechanical properties of welded joints of VT23 titanium alloy received by method of laser welding after modifying the surface layers by ultrasonic mechanical forging (Treatment 1 and Treatment 2) were investigated. The experimental tests have revealed that the Treatment 2 provides a multiple increase in the relaxation property in fatigue life test. The formation of nonuniform distribution of vanadium, chromium and molybdenum in the welded joint increases the strength and, at the same time, the brittleness of β-phase. Mechanical treatment of the surface layers in the second mode provides a multiple increase in ductility up to 13%, in the as-received condition up to 9.9%. In consequence of plastic deformation, the β-phase intensity reduces twice with Treatment 2 which is related to its clustering. As follows from a presented data, the fatigue life of the VT23 titanium alloy has increased more than threefold.

scholarly journals Compressive Behaviour of 3D Printed Polymeric Gyroid Cellular Lattice Structure

2018 ◽  
Vol 455 ◽  
pp. 012047 ◽  
Author(s):  
Gopal K Maharjan ◽  
Sohaib Z Khan ◽  
Syed H Riza ◽  
SH Masood
Keyword(s):  
Lattice Structure ◽  
Compressive Behaviour ◽  
3D Printed

Structural design for compression strength perpendicular to the grain of timber beams

2010 ◽  
Vol 24 (3) ◽  
pp. 252-257 ◽  
Author(s):  
A.J.M. Leijten ◽  
H.J. Larsen ◽  
T.A.C.M. Van der Put
Keyword(s):  
Compression Strength ◽  
Structural Design ◽  
Timber Beams

Quasi-Static Failure Analysis of Honeycomb Sandwich Beam with Composite Facesheets

2010 ◽  
Vol 160-162 ◽  
pp. 855-859 ◽  
Author(s):  
Li Qing Meng ◽  
Yan Wu ◽  
Shi Zhe Chen ◽  
Xue Feng Shu
Keyword(s):  
Sandwich Beam ◽  
Indentation Test ◽  
Core Material ◽  
Honeycomb Core ◽  
Three Point Bending ◽  
Composite Sandwich ◽  
Sandwich Construction ◽  
Honeycomb Sandwich ◽  
Nomex Honeycomb ◽  
Static Failure

Sandwich construction consists of two thin composite or metal facesheets separated by a core material. Despite extensive researches on the sandwich constructions, their mechanical properties and failure behaviours are still not fully understand. The objective of the paper is to use a experimental and theoretical predicting failure mode for sandwich beam consisting of GFRP facesheets and Nomex honeycomb core. Two kinds of composite sandwich beams are observed in quasi-static three-point bending and indentation test.

Stiffness predictions for closed-cell PVC foams

2016 ◽  
Vol 51 (23) ◽  
pp. 3327-3336 ◽  
Author(s):  
King Him Lo ◽  
Akira Miyase ◽  
Su S Wang
Keyword(s):  
Transversely Isotropic ◽  
Elastic Stiffness ◽  
Core Material ◽  
Polymeric Foams ◽  
Matrix Polymer ◽  
Sandwich Construction ◽  
Closed Cell ◽  
Out Of Plane ◽  
Microstructure Parameters ◽  
Foam Properties

Light-weight polymeric foams are frequently used in composite sandwich construction in which foam core material properties could significantly influence the overall performance of the sandwich structure. Foam mechanical properties usually depend on a number of factors, including foam density, cell microstructure, and properties of foam–matrix polymer. Although the properties of foam–matrix polymer are determined mainly by the properties of the foam base (parent) polymer, they are also affected by other factors such as foam processing conditions. With the large number of material and microstructure parameters that influence foam properties, modeling mechanical behavior of polymeric foams could be quite involved, especially if foam behavior is anisotropic. This paper describes an effort to predict static elastic stiffness of closed-cell PVC foams. PVC foams are modeled as transversely isotropic materials with properties in the foam rise direction different from those in the planar (plane of isotropy) directions. An engineering approach, based on fibrous composites, is developed to predict in-plane and out-of-plane stiffness of PVC foams. The validity of the engineering model for the PVC foam stiffness is first demonstrated through comparison with test results on DIAB H80 foam obtained from a systematic in-house test program. Comparison of the predictions with the stiffness properties reported by a PVC foam manufacturer for various other density foams is also carried out. Good agreements are obtained for the cases studied. Comparison of stiffness predictions obtained in the paper with predictions from other published models of isotropic foam behavior is presented.

Effective stress-strain relations for two-dimensional cellular sandwich cores: Homogenization, material models, and properties

2001 ◽  
Vol 55 (1) ◽  
pp. 61-87 ◽  
Author(s):  
Jo¨rg Hohe and ◽  
Wilfried Becker
Keyword(s):  
Effective Stress ◽  
Large Scale ◽  
Material Behavior ◽  
Core Material ◽  
Two Dimensional ◽  
Stress Strain ◽  
Material Models ◽  
Sandwich Construction ◽  
Specific Effects ◽  
Nonlinear Elastic

The theory of sandwich construction has been an active field of research for more than five decades. Aim of the present article is to review the work dedicated to the theoretical determination of the effective stress-strain material behavior of two-dimensional cellular materials with large-scale cells used as core material of structural sandwich panels. Both, the applied homogenization schemes and the applied material models are considered. Explicit expressions for the linear properties of a variety of basic cell geometries are presented, as well as schemes for the analysis of more general cases. In addition, the incorporation of specific effects such as cell wall imperfections or core face sheet constraints and the analysis of nonlinear elastic and elastic-plastic effective material response are reviewed. This review article includes 148 references.

Sign in / Sign up

Export Citation Format

Share Document