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Lamkit is a design and analysis software package for CFRP composites that includes a wide range of analytical methods and mechanical laws. The software package was developed by the EADS Corporate Research Centre in partnership with several university laboratories (ENS-Cachan, ENSMA Poitiers and IGM Toulouse) and is distributed by Cimpa.
(Published on June-July 2005 – JEC Magazine #18)
Lamkit is an easy-to-use software package for composite laminate analysis. Developed by the EADS Corporate Research Centre in Suresnes, France, Lamkit includes a number of advanced features. These include a lay-up optimisation kit based on genetic algorithms; a standard deviation calculation for laminate properties based on the Monte-Carlo method; a creeprecovery analysis kit; and a wet ageing page. Lamkit calculates most of the basic properties needed for design analysis, such as thermo-elastic properties and laminate strength. It also includes a buckling option and several up-to-date analysis options to increase laminate performance.
The most appealing Lamkit features are: Optimisation
Lamkit includes a laminate lay-up optimisation tool. Based on genetic algorithms, optimal lay-ups are obtained automatically for a very large number of design criteria. Several composite material constraints can be considered at the same time during the optimisation process. Multicriteria and constrained optimisation are supported.
Lamkit gives an easy-to-use Monte-Carlo option to calculate the standard deviation for laminate properties. A normal law with average and standard deviation set by the user is assumed for the different laminate inputs (basic laminate inputs, fibre volume, and ply angles). Through a number of trials, the laminate average properties and standard deviation are calculated.
The behaviour of plates under compressive loadings has to be considered in most structural analyses. This software includes a buckling option in order to obtain reliable design values.
Because most of the current laminated materials are susceptible to humidity absorption, Lamkit includes a 1-D model for wet ageing that allows the user to calculate through-thickness moisture absorption for any laminated plate.
Many structural elements are subjected to severe loading conditions, such as long-time high-temperature conditions. Therefore, creep behaviour must be included in the analysis. Lamkit provides an efficient model for laminate creep recovery under typical time/thermal/ mechanical loadings, with viscoelastic and/or viscoplastic basic ply properties.
JEC Composites Magazine: What is the EADS Corporate Research Centre’s mission?
Didier Guedra-Degeorges: The EADS Corporate Research Centre (CRC) has sites in Germany and France, providing world-class research capabilities in major aeronautical research topics such as materials, processes, structural engineering, systems environment, and information technologies for engineering. The CRC is an operational and strategic asset, and a core actor within the EADS Research and Technology network. It creates added value for EADS by leading innovation and sharing skills, facilities and research activities with the EADS business units and with partners. This long-term partnership with external research organisations, and in particular with university and industrial laboratories, is a key element of group innovation strategy, as evidenced in some areas by the creation of joint research laboratories. EADS CCR is the French component of the EADS CRC. As such, it is usually called “EADS CRC-F”. EADS CCR has a permanent staff of 320 people, 60% of whom are senior scientists. Its objective is to carry out research activities that require a concentration of skills and equipment. These activities correspond to interests across business units in many technical fields, including materials and manufacturing.
J.C.M.: What led you to develop the Lamkit software and how did you go about it?
D. G.-D.: For many years now, the EADS Corporate Research Centre has been carrying out research to simulate the performance of CFRP composites in their operating conditions. Developing original and effective analytical methods for damage, wet aging, and optimisation (among other features) in cooperation with large public laboratories led us in 2000 to include the methods in a software platform so as to facilitate technology transfer to the EADS group business units in France, Germany, the UK, and Spain. Given the success of this strategy at EADS, we felt that distributing a public version for industry and universities would be an opportunity to develop our high-tech tool into a new standard. We developed a first-rate partnership with the Cimpa Company to develop and distribute the Lamkit platform.
J.C.M.: Do composite materials have a special role to play in your strategy?
D. G.-D.: Composite materials are a crucial issue in improving the performance of aerospace structures in terms of low weight and maintainability. In civil aviation, the launch of the “all-composite” Boeing 787 will be a strong driver in the response of European aviation to this challenge. Consequently, making tools available that can contribute to the optimum design of composite structures will be an essential requirement in the coming years.
J.C.M.: Are you planning to develop new products and/or services that are dedicated to composite materials?
D. G.-D.: The EADS Corporate Research Centre (Suresnes), is doing a lot of research into innovative processing methods for composites. Developing new products such as high-performance resins for RTM injection or sprays for making dry textile preforms is an important objective, and so is developing new techniques such as braiding, automated preform stitching and nailing, and high-speed lay-up of thermoplastic prepregs. To help with the choice and optimisation of a process, very soon new functions for simulating some processes – polymerisation, RTM injection, etc. – will also be proposed as part of the Lamkit platform.