RECONSTRUCTION AND CALIBRATION OF THE DEVICE FOR MEASURING THE IMPACT TOUGHNESS OF METALS ACCORDING TO CHARPY

U ovom završnom radu izvršena je rekonstrukcija već postojećeg uređaja za ispitivanje udarne žilavosti materijala po Charpyju. Uređaj je bilo potrebno rekonstruirati zbog pojave vibracija i kao posljedice rasipanja energije postojećeg bata, a time do većih mjerenih vrijednosti udarne žilavosti materijala. Do pojave vibracija dolazi zbog odstupanja težišta od točke udara, a time do pojave momenta savijanja koji uzrokuje vibracije. Dano je više mogućih varijanti, a na kraju je usvojena varijanta koja zadovoljava sve postavljene zahtjeve. Izvršena je konstrukcijska razrada usvojene varijante, proračunate su i raspoređene mase pokretnog dijela bata t ako da se težište poklapa s točkom udara. Izvršena je i rekonstrukcija nosivog krana tako da su omogućene dvije početne pozicije bata i to za energiju 150 i 300J kako bi se mogli ispitivati žilaviji i krti materijali.In this final thesis, a reconstruction of an existing Charpy impact toughness testing device was carried out. The device needed to be reconstructed due to the occurrence of vibrations and the consequent energy dissipation of the existing hammer, resulting in higher measured values of material impact toughness. Vibrations occur due to the deviation of the center of gravity from the point of impact, leading to the occurrence of bending moments that cause vibrations. Several possible variants were considered, and in the end, the variant that met all the specified requirements was adopted. A design analysis of the adopted variant was performed, and the masses of the moving part of the hammer were calculated and distributed to align the center of gravity with the point of impact. The supporting crane was also reconstructed to enable two initial positions of the hammer, one for 150J and another for 300J energy levels, in order to test both tougher and more brittle materials