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Abstract(s)
A medição e análise de vibrações a bordo das unidades navais é essencial para a
identificação de dano em estruturas e máquinas de forma a garantir a segurança da
tripulação, uma maior fiabilidade das máquinas e uma maior disponibilidade dos navios
no cumprimento das missões atribuídas.
Ao longo dos tempos surgiram normas, assim como regras de sociedades
classificadoras que, através da medição de vibrações, definem limites que quando
ultrapassados indicam a existência de danos ou anomalias nas máquinas. Estas normas
e regras possuem critérios e padrões de aceitação bem reconhecidos. No entanto,
existem diferenças entre essas normas e regras principalmente em relação aos
parâmetros e critérios de severidade de vibração na deteção de dano em máquinas.
Durante o ciclo de vida da máquina irão surgir desgastes, sujidade e erosões que
alterarão a distribuição de massa do veio ou do rotor de uma máquina e,
consequentemente, o seu desequilíbrio. Assim, baseando-se no dano desequilíbrio
como sendo uma das principais causas de vibrações e avarias em máquinas rotativas,
serão realizadas pesquisas nesta área para fazer a comparação entre as normas e regras.
Como exemplo destas normas e regras, destaca-se a norma ISO 1940 e as regras das
principais sociedades classificadoras ao nível da indústria marítima, com alto nível de
desempenho, como a ABS (American Bureau of Shipping), a DNV-GL (Det Norske Veritas
Germanischer Lloyd), entre outras.
A norma ISO 1940 é uma norma especifica em equilibragem e quantifica o grau
de desequilíbrio de rotores rígidos. Já as outras normas e regras são mais gerais
relativamente à avaliação da vibração nas máquinas. Deste modo, compara-se a ISO
1940, que determina quando é necessário proceder-se a uma equilibragem, com
normas e regras internacionais, que determinam quando é necessário corrigir-se uma
anomalia sem especificar qual. Para tal, criou-se duas simulações, um modelo de uma
máquina em WorkingModel e outro em SolidWorks para a realização de experiências
em que o único dano induzido de forma controlada foi o desequilíbrio. Também criou-se um programa em LabVIEW para medir vibrações e detetar
possíveis danos, na sua fase inicial, através de uma monitorização constante ou “online”
de diversas máquinas. Este programa baseia-se na deteção pelas normas e regras e
ainda permite a comparação destas mesmas normas e regras averiguando qual será a
mais exigente e a mais sensível.
Vibration measurement and analysis on board naval units is essential for identifying damage to structures and machinery to ensure crew safety, greater reliability of machinery and greater availability of ships for assigned tasks. Over time standards have emerged, as well as rules of classification societies which, through the measurement of vibrations, define limits which, if exceeded, will indicate the existence of damage or anomalies in the machinery. These standards and rules have currently well recognized criteria and acceptance standards. However, there are differences between these standards and rules mainly regarding the parameters and criteria of vibration severity in the detection of damage in machines. Throughout the life of the machine, wear, dirt, erosion will arise which will alter the mass distribution of the shaft or rotor of a machine and, consequently, its imbalance. Thus, based on the unbalance damage as one of the main causes of vibrations and breakdowns in rotating machines, research will be conducted in this area to make the comparison between standards and rules. As an example of these standards and rules, the ISO 1940 standard and the rules of the main classification societies in the maritime industry with a high level of performance such as ABS (American Bureau of Shipping), DNV-GL (Det Norske Veritas Germanischer Lloyd), among others, stand out. ISO 1940 is a specific standard in balancing and quantifies the degree of imbalance of rigid rotors. The other standards and rules are more general regarding the evaluation of vibration in machines. This compares with ISO 1940, which determines when balancing is necessary, with international standards and rules, which determine when an anomaly needs to be corrected without specifying which. For this, two simulations were created, one model of a machine in WorkingModel and another in SolidWorks to perform experiments in which the only damage induced in a controlled way was the imbalance. It was also created a program in LabVIEW capable of detecting possible damage in its initial phase through constant monitoring or "online" of several machines. This program is based on the detection by standards and rules and still allows the comparison of these same standards and rules by determining which will be the most demanding and the most sensitive.
Vibration measurement and analysis on board naval units is essential for identifying damage to structures and machinery to ensure crew safety, greater reliability of machinery and greater availability of ships for assigned tasks. Over time standards have emerged, as well as rules of classification societies which, through the measurement of vibrations, define limits which, if exceeded, will indicate the existence of damage or anomalies in the machinery. These standards and rules have currently well recognized criteria and acceptance standards. However, there are differences between these standards and rules mainly regarding the parameters and criteria of vibration severity in the detection of damage in machines. Throughout the life of the machine, wear, dirt, erosion will arise which will alter the mass distribution of the shaft or rotor of a machine and, consequently, its imbalance. Thus, based on the unbalance damage as one of the main causes of vibrations and breakdowns in rotating machines, research will be conducted in this area to make the comparison between standards and rules. As an example of these standards and rules, the ISO 1940 standard and the rules of the main classification societies in the maritime industry with a high level of performance such as ABS (American Bureau of Shipping), DNV-GL (Det Norske Veritas Germanischer Lloyd), among others, stand out. ISO 1940 is a specific standard in balancing and quantifies the degree of imbalance of rigid rotors. The other standards and rules are more general regarding the evaluation of vibration in machines. This compares with ISO 1940, which determines when balancing is necessary, with international standards and rules, which determine when an anomaly needs to be corrected without specifying which. For this, two simulations were created, one model of a machine in WorkingModel and another in SolidWorks to perform experiments in which the only damage induced in a controlled way was the imbalance. It was also created a program in LabVIEW capable of detecting possible damage in its initial phase through constant monitoring or "online" of several machines. This program is based on the detection by standards and rules and still allows the comparison of these same standards and rules by determining which will be the most demanding and the most sensitive.
Description
Keywords
Análise de vibrações Deteção de dano Severidade da vibração Normas de vibrações Sociedades Classificadoras Desequilíbrio