Análisis de sensibilidad de los parámetros de configuración de un proceso de soldadura GMA

El proceso de soldadura GMA en la fabricación de componentes mecánicos es una técnica difícil de ajustar debido al elevado número variables de configuración necesarias. A pesar de ello, dicho proceso se ha aplicado con éxito en múltiples sectores a lo largo del siglo XX. El ajuste óptimo de las variables de configuración es una tarea complicada ya que las desviaciones producen un incremento en las tensiones y deformaciones residuales en la pieza resultante. En el presente trabajo, un análisis de sensibilidad fue realizado para determinar la influencia de cada uno de los parámetros de configuración del proceso y posteriormente, poder establecer un orden de importancia. Un caso práctico de la soldadura de dos placas de acero fue realizado para realizar una lectura de datos y aplicar el análisis de sensibilidad.MAG welding process in manufacturing of mechanical components is a difficult technique to adjust due to the high number of necessary configuration variables. However, this process has been applied successfully in several fields throughout the Twentieth Century. The optimal adjustment of the settings is a complex task because mistakes generate an increase in residual stresses and strains in the manufactured device. In present work, a sensitivity analysis was performed to determine the influence of each of the settings of the process and to establish an order of relevance. A case study of a GMA welding process was performed using two steel plates in order to obtain experimental data for sensitivity analysis

Optimización de un freno de disco mediante la combinación del método de los elementos finitos y algoritmos genéticos

Un freno de disco es un sistema de frenado que actúa sobre las ruedas motrices de los vehículos. Este dispositivo transforma toda o parte de la energía cinética del vehículo debida al movimiento en calor a fin de detenerlo o disminuir su velocidad. Cualquier freno de disco posee una parte móvil (el disco) y una rueda que gira, así como unas pastillas de fricción o de freno. Estas pastillas son los elementos que ejercen la presión y la adherencia sobre los propios discos. Hoy en día, el diseño de este tipo de dispositivos está basado tanto en estudios teóricos como en el Método de los Elementos Finitos (MEF). Uno de los principales inconvenientes de éste método es el ajuste de las condiciones de contorno del modelo y de los parámetros de material. En este trabajo, se muestra el ajuste y la validación experimental de un modelo de elementos finitos de un freno de disco completo. Este ajuste y validación del modelo se realizó mediante técnicas de Algoritmos Genéticos (GA).A disc brake is a braking system that acts on the driving wheels of the vehicles. This device transforms all or part of the vehicle's kinetic energy into heat due to movement to stop or reduce the velocity. Any brake disk has one moving part (the disk) and a spinning wheel, and also brake pads. These pads are the elements that exert pressure and grip on the discs. Today, the design of these devices is based on theoretical studies and in the Finite Element Method (FEM). One of the main disadvantages of this method is the adjustment of the boundary conditions and material parameters of the model. In this paper, is shown the fit and experimental validation of a finite element model of a complete disc brake. This setting and model validation was performed using genetic algorithm techniques

A Comprehensive Review of Fatigue Strength in Pure Copper Metals (DHP, OF, ETP)

Due to their exceptional electrical and thermal conductivity properties, high-purity copper (Cu-DHP) and copper alloys of similar composition, such as electrolytic tough-pitch (ETP), oxygen-free electronic (OFE) and oxygen-free (OF), have often been used in the manufacture of essential components for the electrical, electronic and power generation industries. Since these components are subject to cyclic loads in service, they can suffer progressive structural damage that causes failure due to fatigue. The purpose of this review is to examine the most relevant aspects of mechanical fatigue in Cu-DHP, ETP, OFE and OF. The impact of many factors on fatigue strength (Se), including the frequency, temperature, chemical environment, grain size, metallurgical condition and load type, were analyzed and discussed. Stress–life (S-N) curves under zero mean stress (σm = 0) were found for high-cycle fatigue (HCF). For non-zero mean stress (σm ≠ 0), stress curves were based on a combination of Gerber, Soderberg and ASME elliptic failure criteria. Stress–life (S-N) curves were also developed to correlate fatigue strength (Se) with stress amplitude (σa), yield strength (Syp) and ultimate strength (Sut). Finally, for low-cycle fatigue (LCF), strain–life (ε-N) curves that establish a relationship between the number of cycles to failure (N) and total strain amplitude (εplastic) were determined. Hence, this review, as well as the proposed curves, provide valuable information to understand fatigue failure for these types of materials