Detekcija napak v feromagnetnih materialih z metodo vrtinčnih tokov

MARKL, MATIC (avtor), Fišer, Rastko (mentor)

V pričujočem delu so predstavljene neporušne metode za preiskave feromagnetnih materialov. Podane so teoretične osnove, na katerih slonijo preiskave z magnetnimi delci, ultrazvočne preiskave in preiskave z induciranjem vrtinčnih tokov v materialu. Pri vsaki metodi je predstavljena osnovna oprema za izvajanje preiskave. Opisane so tudi preostale možnosti uporabe posameznih metod, poleg iskanja nepravilnosti v materialu. Predstavljen je postopek konstrukcije sonde za izvajanje preiskav z vrtinčnimi toki. Izdelanih je bilo več simulacijskih modelov. Po predstavljenem kriteriju je izbrana optimalna konstrukcija detekcijske sonde. Ovrednoteni so bili vsi parametri sonde, ki vplivajo na verjetnost zaznave napake. Poleg praktične izvedbe sonde je bil razvit tudi konstantni sinusni tokovni vir in električni vezji za vzorčenje vzbujalnega toka ter detekcijske napetosti. Izdelan je bil tudi uporabniški vmesnik za krmiljenje preiskav. Program zajame in obdela električne parametre in jih grafično predstavi uporabniku. Uspešna detekcija napake v zavornem disku iz sive litine je bila potrjena s simulacijskimi izračuni. S konstruirano sondo so bile na realnem vzorcu testirane enake napake kot tiste v simulacijah. Izvršena je primerjava rezultatov in predstavljeni so predlogi za nadgradnjo merilnega sistema.

• Jezik: Slovenski jezik
• Ključne besede: indikacija, preiskava, magnetno polje, vrtinčni toki, sonda
• Vrsta gradiva: Magistrsko delo/naloga
• Organizacija: FE - Fakulteta za elektrotehniko
• Leto izida: 2018
• PID: 20.500.12556/RUL-101812
• Datum objave v RUL: 06.07.2018

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Fault detection in ferromagnetic materials by eddy current method

Izvleček

The thesis addresses a method for non-destructive testing of ferromagnetic materials with an eddy current probe. Theoretical background of magnetic particles, ultrasonic and eddy current testing are discussed, as well as necessary equipment for performing each examination. Besides testing of material for irregularities, other possible applications of presented methods are also commented. Procedure of constructing the probe for examination of materials with eddy currents through simulations is presented. Simulations were made on multiple simulation models. Different probes were compared with presented criteria. All probe's geometrical parameters, which affect on probability of detecting irregularities, were evaluated and discussed. Besides the practical version of the probe, a constant sine current source and electrical circuits for sampling of the exciting current and detection voltage were constructed. An user interface for controlling the examination procedure was developed. The program also processes acquired electrical signals and presents them graphically to the operator. Successful detection of irregularities in cast iron brake disc was confirmed through simulations. The same irregularities as in simulations were tested with the developed probe. Comparison between simulation and measurement results was conducted and some further improvements of measuring systems were proposed.

• Ključne besede: indication, testing, magnetic field, eddy current, probe