Modelo analítico de impacto em material composto aplicado ao projeto de capacetesIn this work, the energy and stress necessaries to cause permanent damage to a small-scale helmet surface made by composite materials have been investigated. The helmets made by lamination of epoxy resin with glass, Kevlar, carbon and jute fibers were submitted to an impact test based on the Snell M2005 testing procedure. The experimental results were paired up with the predicted values by the mathematical model. From the tendency observed on the result data, the material behaviour can be predicted successfully by the proposed model at the tested conditions.

Neste trabalho foram analisadas matematicamente as energias e tensões necessárias para causar dano permanente à superfície de um capacete em escala fabricado em materiais compósitos. Os capacetes confeccionados a partir da laminação de resina epóxi com fibras de vidro, Kevlar, carbono ou juta foram submetidos a um ensaio de impacto baseado na norma Snell M2005. Os resultados experimentais foram confrontados com os previstos pelo modelo matemático proposto. Observou-se, a partir da tendência dos resultados que o comportamento do material pode ser previsto de modo satisfatório pelo modelo proposto nas condições testadas.

Purpose – A combination of the Analytic Hierarchy Process (AHP) and the Borda’s Method as a suggestion for collective decision-making. By harmonizing the cardinal scale, resulting from the AHP, with the Borda’s Method, it is expected that the evaluations of the alternatives for new helicopters maximize the individual opinions in the construction of a collective decision. Design/methodology/approach – Qualitative and quantitative. The agents involved in the project of acquisition of helicopters for General Usage and Small Capacity for the Brazilian Navy were interviewed, ten pilots and six military engineers from Aeronautics Board of the Brazilian Navy in Rio de Janeiro. The data were treated by combining the cardinal scale resulting from the AHP with the method proposed by Borda. Findings – Analyzing the MGP’s obtained by AHP, it was possible to ascertain that judgment inconsistencies did not affect the result. It is considered that both methods are capable to promote a helpful decision aid inside the BN in the decision upon the purchase of an aircraft to substitute and enhance their naval aviation fleet. It is also considered that both methods can be applied in similar situation of decisions between mutually exclusive alternatives. Originality/value – The usage of hybrid decision aids (created by the combination of methods) in a multicriteria analysis helps organizations make the best use of available resources, especially in complex decision scenarios. This study helps decision-makers to reflect about the process’ tolerance limits. Keywords - Collective decisions; Multicriteria; Borda's Method; Analytic Hierarchy Process.