US 12,270,732 B2
Method and apparatus for determining upvalue factors for expansion measurements on machine elements
David Rittinger, Munich (DE); Ulrich Retze, Munich (DE); Joerg Reschke, Munich (DE); Wilhelm Meir, Munich (DE); Michael Junge, Munich (DE); and Stefan Schwarz, Munich (DE)
Assigned to MTU Aero Engines AG, Munich (DE)
Appl. No. 17/783,797
Filed by MTU Aero Engines AG, Munich (DE)
PCT Filed Dec. 8, 2020, PCT No. PCT/DE2020/000322
§ 371(c)(1), (2) Date Jun. 9, 2022,
PCT Pub. No. WO2021/115512, PCT Pub. Date Jun. 17, 2021.
Claims priority of application No. 10 2019 219 387.0 (DE), filed on Dec. 11, 2019.
Prior Publication US 2023/0008848 A1, Jan. 12, 2023
Int. Cl. G01M 5/00 (2006.01); G01B 11/16 (2006.01); G06F 30/23 (2020.01)
CPC G01M 5/0041 (2013.01) [G01B 11/16 (2013.01); G01M 5/0091 (2013.01); G06F 30/23 (2020.01); G01M 5/0066 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method for determining a scaling factor for a strain measurement in a machine element, comprising the following steps:
placing a strain measurement device on a measurement surface portion of the machine element;
bringing about a static or dynamic deformation of the machine element;
while the static or dynamic deformation of the machine element is being brought about, measuring a strain in the measurement surface portion by use of the strain measurement device;
while the static or dynamic deformation of the machine element is being brought about, measuring a displacement of at least one detection surface portion of the machine element that differs from the measurement surface portion by optical scanning of the machine element;
determining a displacement field on a surface of the machine element on the basis of a model of the machine element and the measured displacement of the at least one detection surface portion;
determining a strain field on the surface of the machine element on the basis of the determined displacement field and the model of the machine element; and
determining a scaling factor from the strain measurement device on the basis of the measured strain in the measurement surface portion and the determined strain field; the scaling factor being a ratio of a strain in the strain field and the measured strain in the measurement surface portion.