The precision of machining systems is ever increasing in order to keep up with components’ accuracy requirements. At the same time product variants areincreasing and order quantities are decreasing, which introduces high demands on the capability of machining systems. The machining system is an interaction between the machine tool structure, the process and the control system and is defined in terms of capability by the positional, static, dynamic and thermal accuracy. So far, the control of the machining system, in terms of static and dynamic stability is process based which is often translated into sub-optimum process parameters and therefore low productivity.This thesis proposes a new approach for control of the machining systemwhich is based on the capability to control the structural properties of themachine tool and as a result, controlling the outcome of the machining process.The control of the structural properties is realized by carefully designed Joint Interface Modules (JIMS). These modules allow for control of the stiffness and damping of the structure, as a result of tuning the contact conditions on the interface of the JIM; this is performed by control of the pre-load on the interface,by treatment of the interface with damping enhancing materials, or both. The thesis consists of a presentation of the motivation behind this work, the theoretical basis on which the proposed concept is based and a part describing the experimental investigations carried out. Two prototype JIMs, one for a milling process and one for a turning process were used in the experimental investigations that constitute the case studies for examining the validity of the proposed concept and demonstrating its applicability in a real production environment. / <p>QC 20140611</p> / EU FP7 POPJIM

Submitted by Kamila Costa (kamilavasconceloscosta@gmail.com) on 2015-07-03T19:40:13Z No. of bitstreams: 2 Dissertação-José C Feitoza.pdf: 2651343 bytes, checksum: 7a35d74605d8cb0399047e68bf28ebaf (MD5) ficha_catalográfica.pdf: 1964 bytes, checksum: 433c944e93f4431471bf2eccf730679e (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-13T15:06:21Z (GMT) No. of bitstreams: 2 Dissertação-José C Feitoza.pdf: 2651343 bytes, checksum: 7a35d74605d8cb0399047e68bf28ebaf (MD5) ficha_catalográfica.pdf: 1964 bytes, checksum: 433c944e93f4431471bf2eccf730679e (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-13T15:17:35Z (GMT) No. of bitstreams: 2 Dissertação-José C Feitoza.pdf: 2651343 bytes, checksum: 7a35d74605d8cb0399047e68bf28ebaf (MD5) ficha_catalográfica.pdf: 1964 bytes, checksum: 433c944e93f4431471bf2eccf730679e (MD5) / Made available in DSpace on 2015-07-13T15:17:35Z (GMT). No. of bitstreams: 2 Dissertação-José C Feitoza.pdf: 2651343 bytes, checksum: 7a35d74605d8cb0399047e68bf28ebaf (MD5) ficha_catalográfica.pdf: 1964 bytes, checksum: 433c944e93f4431471bf2eccf730679e (MD5) Previous issue date: 2015-04-29 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study evaluated two cold flexible pavement recycling techniques "in situ" with the addition of Portland cement (CP II E 32) for the base layer, through analysis of the laboratory tests results and reviews of experimental sections performed on Highway Visconde Porto Seguro / SP, called SP 332, in the granting of DER-SP. Laboratory tests were conducted to prove the influence of the variability of the aggregates and the effect of Portland cement content in the dosage of recycled cold mixtures using mechanical behavior results as evaluation criteria in order to certify the technical quality of recycling layer base. The design of the passages in the experimental track allowed the determination of the flexible pavement recycling methods in situ with the mobile plant KMA 200 and the Wirtgen 2500S equipment for recycling. The monitoring the implementation, by companies, helped to understand the advantages and limitations the set of equipment employed in both recycling techniques of the experimental lane. The monitoring of experimental sections, during and after the construction process, allowed to verify that the cold recycling solution of flexible pavement for technical study, is beneficial to the structural and functional condition thereof. / Esta pesquisa avaliou duas técnicas de reciclagem a frio de pavimentos flexíveis in situ com adição de cimento Portland (CP II E 32) para camada de base, por meio de análises dos resultados de ensaios laboratoriais e avaliações de trechos experimentais executados na Rodovia Visconde de Porto Seguro/SP, denominada de SP 332, sob a concessão do DER-SP. Os ensaios laboratoriais foram conduzidos a fim de comprovar a influência da variabilidade dos agregados e o efeito do teor de cimento Portland na dosagem de misturas recicladas a frio, utilizando resultados de comportamento mecânico como parâmetros de avaliação para atestar a qualidade técnica da reciclagem da camada de base. A concepção dos trechos na pista experimental permitiu determinar os métodos de reciclagem do pavimento flexível in situ com a usina móvel KMA 200 e com a recicladora Wirtgen 2500 S. O acompanhamento da execução, pelas empresas fomentadoras, contribuiu para compreender as vantagens e limitações do conjunto de equipamentos empregados nas duas técnicas de reciclagem da pista experimental. O monitoramento dos trechos experimentais, durante o processo construtivo e posterior a execução, permitiu verificar que a solução de reciclagem a frio do pavimento flexível para as técnicas em estudo, é benéfica para a condição estrutural e funcional dos mesmos.

In this thesis the Ramberg-Osgood nonlinear model for describing the behavior of many different materials is investigated. A brief overview of the model as it is currently used in the literature is undertaken and several misunderstandings and possible pitfalls in its application is pointed out, especially as it pertains to more recent approaches to finding solutions involving the model. There is an investigation of the displacement of a cantilever beam under a combined loading consisting of a distributed load across the entire length of the beam and a point load at its end and new solutions to this problem are provided with a mixture of numerical techniques, which suggest strong mathematical consistency within the model for all theoretical assumptions made. A physical experiment was undertaken and the results prove to be inaccurate when using parameters derived from tensile tests, but when back calculating parameters from the beam test the model has a 14.40% error at its extreme against the experimental data suggesting the necessity for further testing.

The aim of the presented thesis is to create a compact publication which deals with properties, solution and examination of behavior of dynamical systems as models of mechanical structures. The opening portion of the theoretical part leads the reader through the subject of description of dynamical systems, offers solution methods and investigates solution stability. As the introduction proceeds, possible forms of structure loading, damping and response are presented. Following chapters discuss extensively the possible approaches to system behavior observation and identification of nonlinear and chaotic phenomena. The attention is also paid to displaying methods and color spaces as these are essential for the examination of complex and sensitive systems. The theoretical part of the thesis ends with an introduction to fractal geometry. As the theoretical background is laid down, the thesis proceeds with an application of the knowledge and shows the approach to numerical simulation and study of models of real structures. First, the reader is introduced to the single pendulum model, as the simplest model to exhibit chaotic behavior. The following double pendulum model shows the obstacles of observing systems with more state variables. The models of free rod and cantilever serve as examples of real structure models with many degrees of freedom. These models show even more that a definite or at least sufficiently relevant monitoring of behavior of such deterministic systems is a challenging task which requires sophisticated approach.