A new Dual Boundary Element formulation is presented, which allows for the analysis of mechanically fastened repairs and lap joints. The method requires only the boundaries of the problem to be discretized and the fasteners location is simply defined by a set of internal points.The technique enables the evaluation of fastener forces, sheet stresses and the stress intensity factors which are important parameters for a Damage Tolerance assessment.Examples of applications to repair designs and to a lap joint are presented to demonstrate the robustness of the new formulation that is proposed in this paper. NOMENCLATURE a = crack length b, bj, bf" = fastener forces D , = total number of fasteners in the m-th patch E = Young's modulus G = shear modulus h, h , = thickness K , , K , , Kn. KO = stress intensity factors L = crack tip element length M = total number of patches p = fastener pitch R =total fastener force tj, tj'-= boundary tractions uj, u!= = boundary displacements K = material constant v = Poisson's coefficient oij, aim = sheet and patch stresses obr = fastener hole bearing stress ow = sheet gross stress 4 = fastener diameter ' & Uij, S, , , Dijl =fundamental solutions r, Gm, r -oundaries @, Qrn = fastener shear flexibility coefficient s1, OPm = domains A@', Aul D b I b -crack opening displacements
Abstract. In programming languages courses, the difficulty that many students have to learn this subject is notorious, because besides being abstract and conceptual, in the beginning, the course requires a lot of practice, and requires the student to think by a computational way in several solutions for problems using programming.
IntroduçãoCostumeiramente, no ensino técnico de áreas tecnológicas como Informática, Mecatrônica e afins, muitos alunos demonstram dificuldades de aprendizado nas disciplinas de linguagem de programação. São vários os fatores que causam essa situação, dentre os quais podemos citar: dificuldade de desenvolvimento do raciocínio lógico, falta de percepção sobre onde e como aplicar esses conhecimentos, desânimo causado por esses motivos e também por assumir que terá muita dificuldade em conseguir aprovação na disciplina [Ribeiro et al. 2011; Cambruzzi et al. 2015]. A grande quantidade de informações novas que os alunos precisam aprender logo nas primeiras etapas do curso são normalmente conceitos e abstrações, estudados apenas em sala de aula, no projetor de slides, com exemplos no caderno, e pouca experimentação prática, dificultando o entendimento e consequentemente, o desenvolvimento do raciocínio lógico [Ribeiro et al. 2011; Zanetti et al. 2015; Cambruzzi et al 2015].
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.