Loja et al. / Usak University Journal of Material Sciences 1 (2013) 45 – 60 *Corresponding author: Tel: +351 21 831 70 00/1306, Fax: +351 21 841 96 34 E-mail: amelialoja@dem.isel.ipl.pt DOI: http://dx.doi.org/10.12748/uujms/20131711 ©2013 Usak University all rights reserved. 45 Usak University Journal of Material Sciences journal homepage: http://uujms.usak.edu.tr Research article Analysis and optimization of agro waste composite beam structures Maria Amélia Ramos Loja a,b,c* , Tiago Alexandre Narciso da Silva a,b,c , Inês de Carvalho Jerónimo Barbosa a,b,c and Carlos Nuno Fernandes Simões a,c a ADEM/ISEL – Mechanical Engineering Department, Lisbon Superior Institute of Engineering, Lisbon, Portugal b IDMEC/LAETA - Institute of Mechanical Engineering, Technical University of Lisbon, Lisbon, Portugal c GI-MOSM/ISEL - Research Group on Modelling and Optimization of Multifunctional Systems, Lisbon Superior Institute of Engineering, Lisbon, Portugal Received 15 August 2012 Revised 05 April 2013 Accepted 03 June 2013 Abstract The present work, is focused on the study of beam type structures made of agro waste composite materials, namely of sawdust and palm kernel shell, and comprises two parts. A first one where the static and dynamic behavior characterization of the structure is carried out using a first order shear deformation theory approach, considering the influence of different fiber constituent’s percentages. In the second part, a few structural optimization case studies are considered concerning different objective functions and constraints, using sequential quadratic programming technique. Both, analysis and optimization studies were developed on a symbolic computation platform. According to the results obtained in the case studies carried out, it can be concluded that they respect the trends that would be expected, taking into account the nature of the parameters studied: the length to thickness ratio, the boundary conditions and the percentages of the reinforcement agents’ mixtures. A final aspect that is worth mentioning is related to the advantages of using such type of platform in research work, which enables for an integrated development and simulation environment, where the libraries access and the functionalities available, enable a more expedite and perceptive way of achieving results. ©2013 Usak University all rights reserved. Keywords: Natural fiber composites, agro waste composites, static and free vibration analysis, and structural optimization 1. Introduction The increasing trend on the use of green composite materials imposes the need for characterizing the corresponding mechanical behavior, as well as to obtain optimum designs for structures made of these materials. This is mainly evident in application fields where the mechanical requisites do not collide to some of these materials shortcomings, namely in terms of durability and strength limits. The trend of using green composite materials can be due to its effective advantages in ecological terms. They have more renewable characteristics and friendly recycling. Moreover, the necessary raw materials