Method of determining tension in a rod
AssigneeFDH Engineering, Inc.
InventorsMark Cesare, J. Darrin Holt
Life of this patent
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Abstract
A method of determining the tension in an elongated rod is described. The method includes impacting the rod and measuring the vibration response of the rod. Further, the method entails generating a theoretical vibration response of the rod based in part at least on the structural properties of the rod. Thereafter, the method entails adjusting the theoretical vibration response to cause the theoretical vibration response to conform with at least a portion of the measured vibration response. Based on the adjusted theoretical vibration response, the tension of the rod is determined.
Claims17
A method of determining the tension in an elongated rod, comprising:
- a. selecting a plurality of rods comprising a subset of a series of elongated rods where each rod in the series is held in a tensioning structure that maintains the tension;
- b. for each rod in the subset of rods:
- i. transversely impacting the rod with an impacting device and measuring the transverse vibration response of the rod,
- ii. decomposing the transverse vibration response and obtaining one or more model frequencies for the rod, and
- iii. transferring the tension in the rod from the tensioning structure to a force measuring apparatus and measuring the tension in the rod;
- c. forming a set of data comprising the measured tension and the corresponding one or more model frequencies for each rod;
- d. performing a regression analysis of the set of data and obtaining a regression equation that relates tension to model frequency or frequencies;
- e. selecting one of the rods in the series that is not included in the subset:
- i. transversely impacting the rod and measuring the transverse vibration response of the rod,
- ii. decomposing the transverse vibration response and obtaining one or more model frequencies for the rod, and
- iii. using the regression equation to compute a value for the tension in the rod.
A method of determining the tension in a subject elongated rod, comprising:
- a. forming a physical model comprising a model rod that is generally analogous to the subject elongated rod and a tensioning structure that holds the model rod;
- b. selecting a series of tension values that span a range of tension values;
- c. for each value in the series of tension values:
- i. adjusting the tension of the model rod in the physical model,
- ii. transversely impacting the model rod with an impacting device and measuring the transverse vibration response of the model rod, and
- iii. decomposing the transverse vibration response and obtaining one or more model frequencies for the model rod;
- d. forming a set of data comprising each tension value and the corresponding one or more model frequencies;
- e. performing a regression analysis of the set of data and obtaining a regression equation that relates the tension to model frequency or frequencies;
- f. transversely impacting the subject elongated rod and measuring a transverse vibration response of the actual elongated rod;
- g. decomposing the transverse vibration response and obtaining one or more model frequencies for the subject elongated rod;
- and
- h. using the regression equation to compute a value for the tension in the subject elongated rod.
Dependencies are inferred from the claim text.