Drop weight impact behaviour of sandwich panels with metallic micro lattice cores

The paper addresses the low velocity, drop weight behaviour of small (100 mm by 100 mm) sandwich panels with CFRP skins. The main point of interest is the core material, and the focus of the paper is in the use of body centred cubic (BCC) micro lattice cores made from Ti 6Al 4V titanium alloy and 316L stainless steel manufactured using selective laser melting. The mechanical behaviour of the micro lattice core is compared to that of conventional aluminium honeycomb. The paper discusses the manufacture and characterisation of the core materials, the measurement of core properties from strut tensile tests, block compression tests and the drop weight impact performance of the panels. Impact performance is expressed in terms of panel penetration. It is shown that the current Ti 6Al 4V BCC micro lattice cores are competitive with aluminium honeycomb, but that there is scope for improvement in Ti 6Al 4V micro strut mechanical properties. The SLM manufacturing process gives lattice structures with open cell architecture, which is an advantage for aerospace applications, and the SLM process can be used to realise a variety of cell lattice geometries

Determination of Elastic Modulus Value for Selectively Laser Melted Titanium Alloy Micro-Struty

Experimental method in determination of elastic modulus (E value) for micro scale specimen can be a debated issue, in the aspect of reliability and robustness of the results. Attention shall be given to the limiting factors which influence the techniques and procedure, such as the sample’s size, properties and geometries. It is also important to incorporate the microstructural effects toward producing a more understandable results. Analysis of tensile property for titanium alloy (Ti-6Al-4V) micro-struts manufactured from selective laser melting (SLM) rapid prototyping technology is presented in this paper. The result is found comparable to a standard value and will be used in future analysis of micro-lattice performance as core material in sandwich structure

THE DYNAMIC BEHAVIOUR OF THE INSTRUMENTED CHARPY TEST

Les caractéristiques dynamiques des essais Charpy sont étudiées au moyen d'un appareil type Hopkinson et de la photoélasticité. On trouve que cette méthode est supérieure à celle que l'on utilise normalement dans les laboratoires d'essai de matériaux, permettant une meilleure interprétation des résultats.The dynamic characteristics of the Charpy test have been studied by means of a Hopkinson bar apparatus and photoelasticity. It is found that this technique permits a clear evaluation of the test results, and is preferable to the standard instrumented pendulum test

The effects of strain rate, temperature and constraint on the large scale yielding fracture initiation behaviour of a mining steel

L'article décrit le mesurage de la résistance dans les conditions de fracture dynamique d'un acier minier. Les conditions de température, du taux de tension et de la constrainte sur le choix du matériel étaient variées. On s'est servi des modèles théoretiques qui existent déjà pour faire l'étude des relations entre les propriétés micro-structurales matérielles et les valeurs mesurées de la résistance.The paper describes the measurement of the dynamic fracture toughness of a mining steel. The conditions of temperature, strain rate and material constraint were varied. Existing theoretical models were used to study the relation between microstructural material properties and measured values of toughness

An experimental study of the dynamic response of notched bars

SIGLEAvailable from British Library Lending Division - LD:D56541/85 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

The Hopkinson pressure bar An alternative to the instrumented pendulum for Charpy tests

SIGLEAvailable from British Library Lending Division - LD:7623.470(OUEL--1566) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Assessment of dynamic test methods for the measurement of fracture toughness

SIGLEAvailable from British Library Lending Division - LD:7623.47(OUEL--1561/85) / BLDSC - British Library Document Supply CentreGBUnited Kingdo