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DE-102024132592-A1 - Testing device and method for testing the load-bearing capacity of a ring-shaped circumferential weld seam

DE102024132592A1DE 102024132592 A1DE102024132592 A1DE 102024132592A1DE-102024132592-A1

Abstract

The invention relates to a method for testing the load-bearing capacity of an annular circumferential weld seam (22) of a rotationally symmetrical component (10) using a test device, in which the component (10) is received by means of the test device, the component (10) is excited by means of a pulsator of the test device, whereby a test system consisting of the component (10) and the test device oscillates at the natural frequency (34) of the test system, which leads to the weld seam (22) being periodically subjected to a tensile stress (30), the natural frequency (34) at which the test system oscillates is determined by means of a detection device of the test device, and it is determined by means of an electronic computing device that damage to the component (10) has occurred as soon as a change in the measured natural frequency (34) of the test system has been detected.

Inventors

  • Karl Gerhard Kuhlen
  • Henning Grafe
  • Reimund Mim
  • Norbert Schroeder
  • Georg Troppmann

Assignees

  • BAYERISCHE MOTOREN WERKE AKTIENGESELLSCHAFT

Dates

Publication Date
20260513
Application Date
20241108

Claims (10)

  1. Method for testing the load-bearing capacity of an annular circumferential weld (22) of a rotationally symmetrical component (10) using a test device, in which: - the component (10) is held by the test device, - the component (10) is excited by means of a pulsator of the test device, causing a test system consisting of the component (10) and the test device to oscillate at the natural frequency (34) of the test system, which results in the weld (22) being periodically subjected to a tensile stress (30), - the natural frequency (34) at which the test system oscillates is determined by means of a detection device of the test device, and - it is determined by means of an electronic computing device that damage to the component (10) has occurred as soon as a change in the measured natural frequency (34) of the test system has been detected.
  2. Procedure according to Claim 1 , characterized in that a first component element (18) and a second component element (20) are connected to each other by means of the weld seam (22) and in the method a first test element (12) of the test device is applied to the first component element (18) and a second test element (14) of the test device is applied to the second component element (20), wherein by relative movement of the test elements (12, 14) to each other the weld seam (22) is periodically loaded with the tensile stress (30).
  3. Procedure according to Claim 2 , characterized in that the test elements (12, 14) are applied to the component (10) to be tested from two axially opposite sides and are moved relative to each other in axial direction (A) to excite the component (10).
  4. Procedure according to Claim 2 or 3 , characterized in that - the first test element (12) is applied to the first component element (18) in such a way that a first contact surface (26) is formed between the first test element (12) and the first component element (18), which extends in a ring shape around a central axis (16) of the component (10), and/or - the second test element (14) is applied to the second component element (20) in such a way that a second contact surface (28) is formed between the second test element (14) and the second component element (20), which extends in a ring shape around the central axis (16) of the component (10).
  5. Procedure according to Claim 4 , characterized in that , in the component (10) tested by means of the test device, the weld seam (22) is arranged in radial direction (R) between the first component element (18) and the second component element (20), and the first component element (18) is arranged on the outside of the weld seam (22) facing away from the central axis (16), and the test elements (12, 14) are applied to the component (10) such that the first contact surface (26) is arranged radially further outwards than the second contact surface (28).
  6. Method according to one of the preceding claims, characterized in that the component (10) is excited by means of a high-frequency pulsator.
  7. Method according to one of the preceding claims, characterized in that the excitation of the component (10) is terminated as soon as it has been determined that the component (10) is damaged.
  8. Method according to one of the preceding claims, characterized in that, depending on the determined natural frequency (34) of the test system before the change in natural frequency (34) due to damage to the component (10) and a duration of the test process until the determined change in natural frequency (34), a lifetime load characteristic of the component (10) is determined.
  9. Method according to one of the preceding claims, characterized in that a gear for a motor vehicle is tested as component (10).
  10. Test device for testing the load-bearing capacity of an annular circumferential weld (22) of a rotationally symmetrical component (10), which is configured to hold the component (10), comprising: - a pulsator configured to excite the component (10) such that a test system consisting of the component (10) and the test device oscillates at the natural frequency (34) of the test system, thereby periodically subjecting the weld (22) to a tensile stress (30); - a detection device configured to determine the natural frequency (34) at which the test system oscillates; and - an electronic computing device configured to determine that damage to the component (10) has occurred as soon as a change in the measured natural frequency (34) of the test system has been detected.

Description

The invention relates to a test device and a method for testing the load-bearing capacity of an annular circumferential weld seam of a rotationally symmetrical component by means of a test device. From the DD 264 514 A1 A method for the rapid determination of the S-N curve in the fatigue strength range is known. This method utilizes a relationship between the damping behavior and the degradation behavior of spring-mass systems to determine the S-N curve. Furthermore, from the US 2004/0011773 A1 A device for inspecting a laser weld is known, comprising a metallic container or tube and a metallic cap. The device includes two laser beam emitters or a scanning laser beam emitter. Furthermore, the device includes a device for positioning the container or tube with the cap in such a position that a first laser beam is directed at a first predetermined position on the cap and the second laser beam is directed at a second predetermined position on the container or tube, or that a scanning laser beam scans the first and second predetermined positions. The device further includes a device for moving the container or tube and the cap to enable scanning of the entire weld. Finally, the device includes a detector for capturing reflected light from the laser beam(s) along the weld. The object of the present invention is to provide a solution which enables a particularly simple, reproducible stress test of a weld seam of a component with loads such as those that occur during the intended use of the component. This problem is solved according to the invention by the subject matter of the independent claims. Further possible embodiments of the invention are disclosed in the dependent claims, the description, and the figures. Features, advantages, and possible embodiments set forth in the description for one of the subject matter of the independent claims are to be regarded, at least analogously, as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as of any possible combination of the subject matter of the independent claims, optionally in conjunction with one or more of the dependent claims. The invention relates to a method for testing the load-bearing capacity of an annular circumferential weld seam of a rotationally symmetrical component using a test device. In particular, the weld seam runs in a ring around a central axis, especially the axis of symmetry, of the rotationally symmetrical component. The method thus performs a weld seam test. The method provides that the component is held by the test device. The component can therefore be inserted or clamped into the test device to be inspected. The component is, in particular, a motor vehicle component. The method further provides that the component is excited by means of a pulsator in the test device, causing a test system consisting of the component and the test device to oscillate at the natural frequency of the test system. The oscillation of the component, particularly in the area of the weld seam, periodically subjects the weld seam to a tensile stress. A force is applied to the component by means of the pulsator, causing the component to vibrate. The fatigue strength of the component can be determined using the pulsator in the fatigue and endurance limits. In particular, the pulsator enables the implementation of a fracture mechanics analysis or a fatigue and service life analysis of the component within the framework of this method. By inducing vibrations in the component using the pulsator, causing both the component and the test fixture to oscillate at their natural frequency, a particularly large number of load cycles of the weld can be performed consecutively. The pulsator is designed to apply the load dynamically to the component, specifically with periodic increases and decreases. Because the weld is subjected to tensile stress periodically, it can be particularly well inspected for failure. Furthermore, the method incorporates a detection device in the test fixture to determine the natural frequency at which the test system oscillates. This detection device specifically includes an accelerometer and/or a frequency transducer. The detection device is thus designed to continuously determine the value of the natural frequency of the oscillating test system. Furthermore, the procedure stipulates that an electronic computing device determines whether damage to the component has occurred as soon as a change in the measured natural frequency of the test system is detected. With the appearance of cracks in the weld seam, the stiffness of the component decreases in the area of the weld, thereby reducing the natural frequency. The frequency of the component decreases, and consequently, the natural frequency of the test system decreases as it moves from the component to the test fixture. Based on the determined natural frequency of the test system, it can be determined whether damage to the compon