Influence of 3D Printing Parameters by FDM Method on the Mechanical Properties of Manufactured Parts

The manufacturing of machine parts with additive methods (AM) is of significant importance in modern industry. The development of 3D printers and all 3D printing technology is impressive. The ability to make parts quickly and relatively cheaply with AM gives excellent opportunities in terms of e.g., shortening the production preparation time. Proper selection of printing parameters allows for a significant reduction of printing time and production costs. Unfortunately, this has different consequences. Due to the course of the printing process and the parameters that can be set, the same product produced with different parameters has different mechanical properties – mainly different strength. This paper presents the impact of 3D printing parameters on the strength of manufactured parts. Strength tests were carried out on samples made in accordance with DIN EN ISO 527-1:2019. The samples were printed in technology FDM from three different materials, i.e. PLA (completely biodegradable), PETG (recycled material) and Smart ABS (material with minimal shrinkage). The tested samples were made in three levels of print filling – 10, 30 and 60% and with different types of filling – line, mesh and honeycomb. A series of static tensile tests were carried out to determine the strength of the samples produced with different printing parameters. Thanks to the obtained test results, it is possible to select the optimal printing parameters depending on the forecast load of the manufactured parts

Variable structural stiffness in frictional energy dissipation with layer elements

This paper presents an experimental and numerical study that allows to evaluate the dissipation of impact energy, proposing a friction damper with the use of layers (LFD) for impact energy dissipation. The study is carried out on a macro scale of contact between the layers and friction elements. The effects of displacement and applied speed are experimentally analyzed. Numerically, the FEM analyses the effects of the preload and the material of the friction layers on the hysteretic behavior of the LFD. The energy dissipation in a cycle increases with respect to the applied displacement. The operating range of the LFD is variable, because the stiffness of the system increases with respect to the applied displacement. The preload applied to the damper varies with respect to the displacement applied. A theoretical approach is established to estimate the energy dissipation of the system with previously defined parameters or, to define the geometry and material of the damper elements for an estimated energy range

IMPACT ENERGY DISSIPATOR WITH VARIABLE STIFFNESS AND DRY FRICTION LAYERS

This paper presents an experimental and numerical study that allows to evaluate the dissipation of impact energy, proposing a friction damper with the use of layers (LFD) for impact energy dissipation. The study is carried out on a macro scale of contact between the layers and friction elements. The effects of displacement and applied speed are experimentally analyzed. Numerically, the FEM analyses the effects of the preload and the material of the friction layers on the hysteretic behavior of the LFD. The energy dissipation in a cycle increases with respect to the applied displacement. The operating range of the LFD is variable, because the stiffness of the system increases with respect to the applied displacement. The preload applied to the damper varies with respect to the displacement applied. A theoretical approach is established to estimate the energy dissipation of the system with previously defined parameters or, to define the geometry and material of the damper elements for an estimated energy range

Bending crashworthiness of elliptical tubes with different aspect ratio and stiffeners

Lateral car collisions are common scenarios that represent one of the top causes of passenger’s fatalities and injuries. For this purpose, the current article investigates the effect of cross-sectional aspect ratio (β) on the crashworthiness performance of elliptical profiles under lateral loads. For this purpose, structures with different aspect ratios (β) were evaluated. Special emphasis was set on modelling progressive damage by the Johnson–Cook (J-C) failure model for aluminum 6063-T5. The accuracy of our numerical results was determined by experimental validation of a first three-point bending model. From the numerical results, an improvement of energy absorption (Ea) and crushing force efficiency (CFE) is achieved as the aspect ratio (β) increases. In this sense, the best CFE performance (0.728) was obtained for a structure with β= 1.50, which means an improvement of 30.59% of Ea and 9.96% of CFE relative to a circular tube. At this point, the limits for sizing of elliptical profiles in terms of (β) were determined by practical equation. To improve even more the crashworthiness capacity of the elliptical profile with β= 1.50, the use of plates in horizontal, vertical, and combined mode was also explored. As a result, the effectiveness of vertical ribs was demonstrated. The highest CFE performance was obtained for a structure vertically reinforced with three ribs, which allowed a further increase of CFE up to 0.805. Then a final improvement in CFE of 21.60% was computed. Finally, an application of our study to a side sill system is also investigated

Consumo voluntário e ganho de peso de borregas das raças Santa Inês, Suffolk e Ile de France, em pastejo rotacionado sobre Panicum maximum jacq. cvs Aruana ou Tanzânia

O objetivo deste trabalho foi determinar o ganho de peso e o consumo voluntário de matéria seca em borregas das raças Santa Inês, Suffolk e Ile de France, em pastejo rotacionado em capim Aruana ou Tanzânia (Panicum maximum Jacq.) com no máximo sete dias de utilização e 42 a 53 dias de descanso, durante o outono (março a maio) de 2001. Foram utilizadas 38 borregas, 12 da raça Santa Inês, 14 da raça Ile de France e 12 da raça Suffolk, com cinco a seis meses de idade, as quais foram distribuídas nos seguintes tratamentos: T1- pastejo em capim Aruana; T2- pastejo em capim Tanzânia. As avaliações da massa de forragem pré-pastejo e pós-pastejo (kg ha-1) foram registradas e a produção fecal determinada para a estimativa do consumo, utilizando-se o indicador óxido crômico. A média de produção do capim Aruana foi de 4260 kg ha-1 e para o Tanzânia foi de 4657 kg ha-1 e os resíduos pós-pastejo foram de 2195 e 2415 kg ha-1, respectivamente. O teor de proteína bruta (PB) foi maior (P< 0,05) para o capim Aruana (11%) do que para o Tanzânia (9%). O teor de FDN foi similar para os dois capins (73%). O baixo ganho de peso médio diário e o consumo de matéria seca não mostraram diferença significativa entre cultivares (35 g e 2,9% do peso vivo, respectivamente), mas os animais da raça Santa Inês mostraram maior consumo de MS, em porcentagem do peso vivo (3,6 %), que os animais das demais raças (2,6%; P< 0,05). Concluiu-se que as forrageiras avaliadas não atenderam às necessidades nutricionais dos animais, levando a ganhos de peso insatisfatórios

Consumo voluntário e ganho de peso de borregas das raças Santa Inês, Suffolk e Ile de France, em pastejo rotacionado sobre Panicum maximum jacq. cvs Aruana ou Tanzânia

O objetivo deste trabalho foi determinar o ganho de peso e o consumo voluntário de matéria seca em borregas das raças Santa Inês, Suffolk e Ile de France, em pastejo rotacionado em capim Aruana ou Tanzânia (Panicum maximum Jacq.) com no máximo sete dias de utilização e 42 a 53 dias de descanso, durante o outono (março a maio) de 2001. Foram utilizadas 38 borregas, 12 da raça Santa Inês, 14 da raça Ile de France e 12 da raça Suffolk, com cinco a seis meses de idade, as quais foram distribuídas nos seguintes tratamentos: T1- pastejo em capim Aruana; T2- pastejo em capim Tanzânia. As avaliações da massa de forragem pré-pastejo e pós-pastejo (kg ha-1) foram registradas e a produção fecal determinada para a estimativa do consumo, utilizando-se o indicador óxido crômico. A média de produção do capim Aruana foi de 4260 kg ha-1 e para o Tanzânia foi de 4657 kg ha-1 e os resíduos pós-pastejo foram de 2195 e 2415 kg ha-1, respectivamente. O teor de proteína bruta (PB) foi maior (P< 0,05) para o capim Aruana (11%) do que para o Tanzânia (9%). O teor de FDN foi similar para os dois capins (73%). O baixo ganho de peso médio diário e o consumo de matéria seca não mostraram diferença significativa entre cultivares (35 g e 2,9% do peso vivo, respectivamente), mas os animais da raça Santa Inês mostraram maior consumo de MS, em porcentagem do peso vivo (3,6 %), que os animais das demais raças (2,6%; P< 0,05). Concluiu-se que as forrageiras avaliadas não atenderam às necessidades nutricionais dos animais, levando a ganhos de peso insatisfatórios

Explorando internet de las cosas basado en ESP8266: herramientas y caso de estudio

El presente proyecto se centra en la exploración del internet de las cosas basado en ESP8266 con el desarrollo de una aplicación para dispositivos móviles que integra el control y monitoreo de un alimentador automático de mascotas. El documento presenta un diseño de una estructura física que porte todos los componentes eléctricos y logre realizar una conexión por medio de un servidor, utilizando el protocolo MQTT para mensajería en tiempo con la aplicación desde cualquier parte del mundo utilizando una red Wifi. Mediante una serie de pruebas de los tiempos de respuesta del alimentador después de entrar a la aplicación y presionar el botón y utilizando la misma red en la que está conectado el alimentador. Los tiempos máximos de respuesta en el servomotor fueron de 5 segundos mientras que los tiempos de respuesta para los sensores fueron de 1 segundos

Método Taguchi para la optimización de parámetros en la simulación numérica del proceso de inyección de plástico

El trabajo plantea el uso de Método Taguchi para la optimización de parámetros en la simulación numérica del proceso de inyección de plástico para reducir el desplazamiento total en el producto. Se identificaron las variables de temperatura de derretimiento, tiempo de enfriamiento, tiempo de llenado, y tiempo de mantención. Se plantea la utilización de diseño de experimentos de Taguchi de tres niveles y cinco factores, que suman un total de 27 iteraciones del experimento. El análisis de señal a ruido determinó que los dos parámetros más influyentes en la disminución de desplazamiento fueron temperatura de derretimiento y tiempo de mantención de presión. Tras el análisis de la varianza y la interpretación de gráficas de señal se plantearon dos experimentos cuyos valores demostraron una mejora de 27 % (5.0349 mm) y 31.43% (4.7485 mm), respectivamente, en comparación a los valores de control (6.9252 mm). Mediante el uso de las herramientas permite. Mediante el uso de Taguchi y SolidWorks plastic se logró disminuir la variación de la deformación y la detección de las principales variables que afectan en el proceso de llenado de la pieza aplicando el método propuesto

Preface

The 8th International Conference of Computational Methods in Engineering Science (CMES’2023), held on November 23rd-25th, 2023 in Puławy, Poland, is organized by the Polish Society for the Promotion of Knowledge, the Lublin University of Technology (Faculty of Mechanical Engineering, Faculty of Electrical Engineering and Computer Science, Faculty of Management, and Faculty of Environmental Engineering), and the Polish Air Force University (Faculty of Aviation). The conference is an excellent opportunity to present and learn how computational methods can be applied in scientific disciplines like mechanical, materials, and civil engineering, management, environmental engineering, mining and energy, computer engineering, and innovative products launched by companies. The interdisciplinary nature of the conference facilitates knowledge sharing among Polish and foreign research centers that represent different engineering and technical sciences disciplines. This edition creates opportunities for plenary sessions and presentations of companies that solve engineering problems with modern computational methods and tools