# US 2014/0190268 A1 · Method for determining the fatigue capital of a cable > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190268 A1 - Document ID: US20140190268A1 - Status: Published application - Kind: A1 - Application number: 14/123,489 - Filed: 2012-06-04 - Published: 2014-07-10 - Earliest claimed: 2011-06-03 - Assignees: Soletanche Freyssinet - Inventors: Gilles Hovhanessian; Alexandre Chaperon; Erik Mellier - Web page: https://patentgrep.com/patent/US20140190268A1 ## CPC - G01N 3/32: by applying repeated or pulsating forces - G01M 5/0025: {of elongated objects, e.g. pipes, masts, towers or railways (G01M5/0058 takes precedence)} - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR ## Abstract The invention relates to a method for determining the fatigue capital of a cable supporting a civil engineering structure, the method including: a measuring step (S1, S2) during which the normal tensile stress in the cable and the bending stress in the cable are measured in a synchronized manner so as to obtain the compound stress in the cable; a counting step (S3) during which a count of the number of stress cycles, depending on the amplitude of the stress, is carried out from the measured compound stresses; and a step (S4) of assessing the fatigue capital of the cable during which the fatigue capital of the cable is determined by comparing the count, carried out in the counting step, with a pre-set Wohler curve for the cable. ## Claims ### Claim 1 Method for determining the fatigue capital of a cable supporting a civil engineering structure, wherein the method comprises: a measurement step (S1, S2) during which the normal tensile force on the cable and the bending force on the cable are synchronously measured so as to obtain the compound force on the cable; a counting step (S3) during which, based on the measured compound forces, a count of the stress cycle number as a function of the amplitude of the force is realized; a step of evaluating the fatigue capital of the cable (S4), during which the fatigue capital of the cable is determined by comparing the count carried out during the counting step with a Wöhler-type curve that has been previously determined for the cable. ### Claim 2 Method according to the preceding claim, wherein measurement of the normal tensile force on the cable is realized directly, for example, by means of a load cell. ### Claim 3 (depends on 1) Method according to claim 1, wherein measurement of the normal tensile force on the cable is realized indirectly, for example, by the use of a strain gauge placed on the anchor or on the cable, by measuring the force on one among a plurality of cable strands, or by the vibrating chord method and using measurement of normal frequencies of vibration of the cable. ### Claim 4 Method according to any one of the preceding claims, wherein measurement of the bending force on the cable is directly realized. ### Claim 5 (depends on 1, 2, 3) Method according to any one of claims 1 to 3, wherein measurement of the bending force on the cable is realized indirectly, for example, based on a measurement of cable movements in a plane intersecting its axis and at a known distance from the anchorage. ### Claim 6 (depends on 5) Method according to claim 5, wherein the measurement of cable movements is realized in a shock absorber placed on the cable to dampen transverse vibrations. ### Claim 7 Method according to any one of the preceding claims, wherein tensile and/or bending measurements are realized at a frequency on the order of 1 Hz to 1 kHz. ### Claim 8 Method according to any of the preceding claims, wherein the measurement step is not realized continuously from the moment of cable installation, and wherein the measured data are used to extrapolate from loads before and after the measurement period. ### Claim 9 Method according to any one of the preceding claims, wherein the measurement step is realized continuously from the time of cable installation so as to measure the tensile and bending forces on the cable from the time of its installation. ### Claim 10 Method according to any one of the preceding claims, wherein the counting step is realized by means of rainflow counting. ### Claim 11 Method according to any one of the preceding claims, wherein the history or extrapolation of past loads is used to compare the fatigue actually experienced by the cable with the assumptions made at the time of construction. ### Claim 12 Method according to any one of the preceding claims, wherein extrapolations of future loads are used to estimate a capacity or residual lifetime of the cable with respect to fatigue. ### Claim 13 Device for determining the fatigue capital of a cable (2) supporting a civil engineering structure (1), wherein the device comprises means for implementing a method according to any one of the preceding claims, that is, comprising: means for measuring the overall tensile force (8) on the cable (2); means for measuring the overall bending force (10) on the cable (2); means for counting (12) the number of stress cycles as a function of the amplitude of tensile and bending forces experienced by the cable; and means for comparing (14) the counting carried out by the counting means with a Wöhler-type curve previously established for the cable. ### Claim 14 Device according to the preceding claim, further comprising alert means (16) for automatic notification whenever the cable's capacity or its residual lifespan is reduced below a predetermined threshold. ### Claim 15 (depends on 13, 14) Device according to any one of claim 13 or 14, wherein the anchoring device of the cable on the civil engineering structure comprises a shock absorber that integrates a sensor for measuring the cable's bending force.