Sökning: "ultrasonic testing"

Visar resultat 1 - 5 av 48 avhandlingar innehållade orden ultrasonic testing.

1. 1. Non-destructive measurement of near-surface cracks in railheads : with focus on ultrasonic inspections

   Författare :Rayendra Anandika; Jan Lundberg; Paul Wilcox; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rail inspection; phased array; ultrasonic testing; eddy current testing; surface cracks; non-destructive testing; NDT; railway; condition monitoring; Drift och underhållsteknik; Operation and Maintenance;

   Sammanfattning : Near-surface cracks in railhead that caused by rolling contact fatigue (RCF) is one of a kind rail defects that degrade rail track quality. Dependent on the trail load, the cracks can reach to severe level quickly. LÄS MER

3. 2. Ultrasonic testing of components produced with additive manufacturing : Towards improved detection and classification of defects

   Författare :Mikael Sahl; Håkan Wirdelius; Erik Lindgren; Oskar Tofeldt; Madis Ratassepp; Högskolan Väst; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Non-Destructive Testing NDT ; Super alloys; Microstructure; Ultrasonic Testing UT ; Productivity Enhancement; Production Technology; Produktionsteknik;

   Sammanfattning : The focus in this work is on the use of ultrasonic testing as a method for inspecting components manufactured through additive manufacturing (AM) processes. The research is rooted in the need for effective non-destructive testingtechniques that can adapt to the unique challenges posed by AM-produced materials, including complex defect geometries and surface conditions. LÄS MER

4. 3. Maximum a posteriori deconvulution of ultrasonic data with applications in nondestructive testing : Multiple transducer and robustness is

   Författare :Tomas Olofsson; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; Ultrasonic pulse-echo testing; nondestructive testing; maximum a posteriori estimation; linear minimum mean squared error estimation; robust filtering; multivariable filtering; sparse deconvolution; Materialvetenskap; Materials science; Teknisk materialvetenskap; Signal Processing; signalbehandling;

   Sammanfattning : In the thesis, various aspects of deconvolution of ultrasonic pulse-echo signals in nondestructive testing are treated. The deconvolution problem is formulated as estimation of a reflection sequence which is the impulse characteristic of the inspected object and the estimation is performed using either maximum a posteriori (MAP) or linear minimum mean square error (MMSE) estimators. LÄS MER

5. 4. Experimental Validation and Applications of a Phased Array Ultrasonic Testing Probe Model

   Författare :Xiangyu Lei; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Simulations; Applications; Nondestructive testing NDT ; Phased array ultrasonic testing PAUT ; Experiments;

   Sammanfattning : New manufacturing technologies are developed to facilitate flexible product designs and production processes. However, the quality of the final products should not be compromised. The assessment of product quality and integrity lies on various inspection methods. LÄS MER

7. 5. Very high cycle fatigue of automotive steels : Testing and computation at 20 kHz

   Författare :Mohamed Sadek; Jens Bergström; Nils Hallbäck; Ulrich Krupp; Karlstads universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Very high cycle fatigue; ultrasonic fatigue testing; automotive steels; fatigue strength; stress intensity computation; crack growth; Materialteknik; Materials Engineering;

   Sammanfattning : Mechanical fatigue failure occurs in components subjected to cyclic loading. A crack initiates at critical regions in the component and propagates during repeated loading. The expected fatigue life depends on the level, type and frequency of the loading. LÄS MER