Repotenciación de la máquina para ensayos de resistencia a la fatiga del Laboratorio de Resistencia de Materiales de la Facultad de Mecánica de la ESPOCH.

Abstract

The present paper aims to repower the machine for resistance tests to the fatigue of the material resistance laboratory of Mechanical Engineering Department at ESPOCH. The mechanical, electrical and electronic systems of the machine were analyzed to verify its current conditions. A solution was established for the implementation of the selected systems by a preliminary study of the systems which could be used and by a weighed evaluation. Afterwards, the design and/or selection of the mechanical system made up of balls bearing, chucks, shafts, plates and load cell was carried out. Structural construction phase was carried out according to the characteristics of the machine design and implementation of the elements of electric command and control made up of a PLC (Programmable Logical Controller) which controls the electrical system functioning, a single-phase engine, switch on push buttons and switch on pilot lights. An encoder was used to count the engine revolutions. It is connected to a High-Speed counting (HSC) of a PLC. The Human Machine interface (HMI) programmed in the software LabView will allow operator to monitor the condition of the machine in real time, visualize the graphic strength vs. number of cycles S-N. When the tests are finished, a report in word format will be written. By repowering this machine, vibration and misalignment were eliminated compared to the first machine. It was easy to gather and get reliable results when practicing in the laboratory. It is recommended to use standardized tests tubes according to E 606 norm of ASTM (American Society of Testing Materials), meet the requirements of the operation manual and maintenance plan to guarantee the machine functioning.