Diseño y fabricación de un banco de ensayos para ensayos de impacto mediante una celda de carga.
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Date
2026
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
La conminución representa una de las operaciones de mayor consumo energético en la industria minera, llegando a concentrar una parte significativa de la energía utilizada en una mina. Debido a que solo una pequeña parte de esta energía es empleada efectivamente en la generación de nuevas superficies de fractura, resulta fundamental desarrollar metodologías experimentales que permitan caracterizar la respuesta materiales sometidos a impacto y estimar la energía asociada a la fractura primaria. En este trabajo se diseñó, construyó y validó un banco de ensayos tipo Drop Weight Test (DWT) mediante una celda de carga, con el objetivo de evaluar su capacidad para caracterizar eventos de fractura por impacto utilizando una alternativa de menor costo respecto a sistemas especializados. Para ello, se implementó una metodología de calibración basada en ensayos de compresión realizados en una máquina universal Zwick Roell Z005, determinándose una rigidez equivalente del sistema de 5206 N/mm y una sensibilidad de 2.34 mV/V para la celda de carga utilizada. Posteriormente se desarrolló un procedimiento de fabricación y manejo de probetas cilíndricas de cemento de 13 mm de diámetro, las cuales fueron utilizadas para validar el sistema experimental. Se realizaron en total 113 ensayos de impacto sobre muestras de cemento y partículas de cuarzo bajo distintas condiciones de velocidad, empleando tanto la celda de carga como un sensor piezoeléctrico PCB Piezotronics 208C05 para comparar el desempeño de ambas técnicas de medición. Los resultados mostraron que la celda de carga es capaz de identificar adecuadamente el instante de impacto, la fractura primaria y la energía específica de fractura asociada, obteniendo valores comparables a los registrados mediante el sensor piezoeléctrico. Para las probetas de cemento, las diferencias observadas en el parámetro e50 fueron inferiores a 10 J/kg para una velocidad de impacto de 1,1 m/s y del orden de 60 J/kg para 1,5 m/s. En el caso del cuarzo, se observó una mayor dispersión experimental atribuida a la heterogeneidad inherente del material. Adicionalmente, los resultados fueron contrastados con ensayos realizados mediante un equipo Ultra Fast Load Cell (UFLC) en el Laboratorio de Tecnología Mineral de la Universidad Federal de Río de Janeiro, obteniéndose tendencias consistentes respecto al comportamiento de fractura primaria de los materiales estudiados. Se concluye que una celda de carga convencional, adecuadamente calibrada, es una alternativa viable para la realización de ensayos de impacto destinados a la determinación de energía específica de fractura primaria, por otro lado, no proporciona una respuesta adecuada para el análisis de la energía de conminución debido a la naturaleza de la celda. La metodología desarrollada proporciona una herramienta experimental reproducible y de bajo costo para estudios de conminución, contribuyendo a la comprensión de los mecanismos de fractura y al desarrollo de estrategias orientadas a mejorar la eficiencia energética de los procesos mineros.
Mining is one of the main pillars of the Chilean economy; however, comminution processes, including crushing and grinding, account for a significant fraction of the energy consumed in mining operations. Improving the understanding of particle breakage mechanisms is therefore essential for increasing energy efficiency in mineral processing. This study presents the design and validation of a low-cost instrumented Drop Weight Test (DWT) bench equipped with a load cell for the characterization of primary fracture energy under impact loading conditions. The experimental setup was designed based on Hertzian contact theory and instrumented with a 2-ton DYMH-102 load cell. A calibration procedure was developed using quasi-static compression tests performed on a Zwick Roell Z005 testing machine, allowing the determination of the load cell stiffness and calibration parameters. In addition, a specimen preparation methodology was established to produce cylindrical cement samples with controlled geometry, ensuring experimental repeatability. A total of 113 impact tests were conducted on cement specimens and quartz particles at impact velocities of 1.1 and 1.5 m/s. The force–time response recorded by the load cell was used to estimate the specific primary fracture energy, which was subsequently compared with measurements obtained using a piezoelectric sensor specifically designed for impact applications. The results showed that the piezoelectric sensor provides a more accurate representation of the impact event due to its superior dynamic response. Nevertheless, after calibration, the load cell produced consistent estimates of primary fracture energy, with differences ranging from approximately 1% to 11% depending on the material and testing conditions. Additional comparisons were performed using data obtained from an Ultra-Fast Load Cell (UFLC) system at the Laborat´orio de Tecnologia Mineral (LTM) at Universidade Federal do Rio de Janeiro, demonstrating that the proposed methodology is capable of capturing trends consistent with established impact characterization techniques. The results indicate that load-cell-based DWT systems represent a technically viable and economically attractive alternative for primary fracture characterization of brittle materials, contributing to the development of more accessible experimental tools for comminution research and energyefficient mining.
Mining is one of the main pillars of the Chilean economy; however, comminution processes, including crushing and grinding, account for a significant fraction of the energy consumed in mining operations. Improving the understanding of particle breakage mechanisms is therefore essential for increasing energy efficiency in mineral processing. This study presents the design and validation of a low-cost instrumented Drop Weight Test (DWT) bench equipped with a load cell for the characterization of primary fracture energy under impact loading conditions. The experimental setup was designed based on Hertzian contact theory and instrumented with a 2-ton DYMH-102 load cell. A calibration procedure was developed using quasi-static compression tests performed on a Zwick Roell Z005 testing machine, allowing the determination of the load cell stiffness and calibration parameters. In addition, a specimen preparation methodology was established to produce cylindrical cement samples with controlled geometry, ensuring experimental repeatability. A total of 113 impact tests were conducted on cement specimens and quartz particles at impact velocities of 1.1 and 1.5 m/s. The force–time response recorded by the load cell was used to estimate the specific primary fracture energy, which was subsequently compared with measurements obtained using a piezoelectric sensor specifically designed for impact applications. The results showed that the piezoelectric sensor provides a more accurate representation of the impact event due to its superior dynamic response. Nevertheless, after calibration, the load cell produced consistent estimates of primary fracture energy, with differences ranging from approximately 1% to 11% depending on the material and testing conditions. Additional comparisons were performed using data obtained from an Ultra-Fast Load Cell (UFLC) system at the Laborat´orio de Tecnologia Mineral (LTM) at Universidade Federal do Rio de Janeiro, demonstrating that the proposed methodology is capable of capturing trends consistent with established impact characterization techniques. The results indicate that load-cell-based DWT systems represent a technically viable and economically attractive alternative for primary fracture characterization of brittle materials, contributing to the development of more accessible experimental tools for comminution research and energyefficient mining.
Description
Tesis presentada para optar al título de Ingeniero/a Civil Mecánico/a.
Keywords
Drop weight testing (Metals), Consumo de energía, Minería