Method of monitoring fatigue of structural component parts, for example, in nuclear power plants
First Claim
1. Method for monitoring fatigue of thermally and/or mechanically stressed structural components having sensors connected to a process computer, comprising:
- (a) feeding values measured by the sensors during a given timing cycle to the process computer;
(b) computing weighting factors in a first arithmetic unit from the measured values and stress data obtained from mechanical unit load cases or specific load case comparative stress data stored in a stress file;
(c) computing in a second arithmetic unit comparative values by weighting the measured values obtained through an acquisition unit with the weighting factors obtained from the first arithmetic unit, stored in the working memory after dissolving the measured values into corresponding weighted unit values obtained from two unit load-case libraries and weighted and stored in synchronism as stress data in a second memory;
(d) steering the second memory by means of a third arithmetic unit for forming a stress distribution curve and obtaining from the stress distribution curve partial usage factors developed during said timing cycle; and
(e) storing cumulatively the partial usage factors in a further working memory being added to the previously stored partial usage factors, obtaining therefrom an overall load factor.
2 Assignments
0 Petitions
Accused Products
Abstract
A method of monitoring fatigue of a stressed component part such as in nuclear power plants or aircraft, with sensors attached to the outside of the component part to be monitored, includes feeding values measured by the sensors at the component parts to be monitored at a given timing cycle to a process computer. The process computer contains a first arithmetic unit (LCID) which determines weighting factors for addressing mechanical unit load cases and/or directly comparing stresses specific to a load case, from the measured values with the aid of a stress file (LCL) of specified unit load cases, and storing them in a working memory. They are assigned in a second arithmetic unit (HSP VSP), in accordance with the comparison stresses determined by the first arithmetic unit (LCID) and/or on the basis of measured data stored in the working memory (FIFO II), after they are resolved in accordingly weighted unit values, utilizing a first memory including two unit load case libraries (TLL, MLL). They are stored in a weighted manner and in a timing cycle in a second memory (STACK VSP). The second memory is controlled with a third arithmetic unit (RFL). A partial usage factor obtained during an evaluation cycle of the component part is calculated from a comparison stress curve, utilizing fatigue curves stored in a memory (FAT). The partial usage value is added to a previous usage factor stored in a further working memory (RAM USE I), whereby an actual overall usage factor (Uges) is obtained.
55 Citations
19 Claims
-
1. Method for monitoring fatigue of thermally and/or mechanically stressed structural components having sensors connected to a process computer, comprising:
-
(a) feeding values measured by the sensors during a given timing cycle to the process computer; (b) computing weighting factors in a first arithmetic unit from the measured values and stress data obtained from mechanical unit load cases or specific load case comparative stress data stored in a stress file; (c) computing in a second arithmetic unit comparative values by weighting the measured values obtained through an acquisition unit with the weighting factors obtained from the first arithmetic unit, stored in the working memory after dissolving the measured values into corresponding weighted unit values obtained from two unit load-case libraries and weighted and stored in synchronism as stress data in a second memory; (d) steering the second memory by means of a third arithmetic unit for forming a stress distribution curve and obtaining from the stress distribution curve partial usage factors developed during said timing cycle; and (e) storing cumulatively the partial usage factors in a further working memory being added to the previously stored partial usage factors, obtaining therefrom an overall load factor. - View Dependent Claims (2, 3, 6, 7, 8)
-
-
9. Apparatus for monitoring fatigue of thermally and/or mechanically stressed structural components, comprising:
-
(a) sensors for measuring values; (b) a process computer having a first arithmetic unit, a stress file and a working memory connected to the process computer for computing weighting factors in the first arithmetic unit from values measured by the sensors and stress data obtained from mechanical unit load cases or specific load case comparative stress data stored in a stress file; (c) a second arithmetic unit for computing comparative values, an acquisition unit for obtaining the measured values, first and second unit load-case libraries and a second memory, for weighting and storing the measured values obtained through the acquisition unit with the weighting factors obtained from the first arithmetic unit, stored in the working memory after dissolving the measured values into corresponding weighted unit values obtained from said first and second unit load-case libraries and weighted and assigned in synchronism in said second memory; (d) a third arithmetic unit for steering the second memory by means of the third arithmetic unit, a stress distribution curve formed by said third arithmetic unit steering said second memory, and obtaining from the stress distribution curve partial usage factors developed during said timing cycle; and (e) a further working memory for storing cumulatively the partial usage factors in the further working memory and adding them to the previously stored partial usage factors, for obtaining therefrom an overall load factor. - View Dependent Claims (4, 5, 10, 11, 12, 13, 14, 15, 16)
-
-
17. Apparatus for monitoring fatigue of a component having a stressed component part, having temperature sensors attached to the outside surface of the component part, the apparatus which comprises:
- means for measuring at given timing cycles the outside surface temperature distribution data for the component;
a load unit stress file for unit load cases for storing the temperature transient responses to elementary temperature transients;
means for determining by regressive analysis best fitting weighting factors to be applied to the temperature transient responses which by superposition thereof provide the best fit with the measured outside surface temperature distribution data;
a first working memory for storing said weighting factors determined by the best fit;
a unit load case stress file for storing elementary comparison stress pattern data, applying said weighting factors thereto for obtaining actual component part stresses;
an arithmetic unit for computing the actual stresses, and using fatigue data for obtaining partial usage factors for the component parts, and a cumulative usage factor memory for storing the partial usage factors. - View Dependent Claims (18, 19)
- means for measuring at given timing cycles the outside surface temperature distribution data for the component;
Specification