A method for determining an undesired condition in an electrical drive system including an electrical machine and an electrical drive, wherein the method includes a) obtaining a measured signal of an electrical or mechanical parameter, b) obtaining a frequency spectrum of the measured signal, that contains a measured frequency component, c) determining whether the measured frequency component is within a predetermined distance from a trend line, which trend line is associated with only one specific frequency component of the electrical or mechanical parameter present during a specific undesired condition, d) on the condition that the measured frequency component is within the predetermined distance from the trend line increasing a counter associated with the trend line, e) repeating steps a) to d), wherein in case the counter reaches a predetermined number determining that the electrical drive system is subjected to the undesired condition associated with the trend line.

A system includes an electromagnetic inspection device, a processing device, and a memory device. The electromagnetic inspection device includes at least one transmitter that can transmit an electromagnetic signal toward a wall of a flexible pipe. The electromagnetic inspection device also includes at least one receiver that can receive at least one scattered electromagnetic signal from the wall of the flexible pipe. The memory device includes instructions executable by the processing device to cause the processing device to transmit an electromagnetic signal using the transmitter, to receive the scattered electromagnetic signal using the receiver, and to identify at least one anomaly in the wall of the flexible pipe using the scattered electromagnetic signal.

A sensor assembly for measuring a torsion of a rotor blade of a wind turbine generator system includes a first light source configured to generate light and a first transmitter-side polarizer disposed downstream thereof in a direction of light propagation and configured to generate linearly polarized light as a first transmission light. A second light source is configured to generate unpolarized light as a second transmission light. First and second detector elements are arranged and adapted to receive the first and second transmission light. A first receiver-side polarizer is disposed upstream of the first detector element in the direction of light propagation and a second receiver-side polarizer is disposed upstream of the second detector element in the direction of light propagation. An orientation of a polarization plane of the first receiver-side polarizer and an orientation of a polarization plane of the second receiver-side polarizer are different from one another.

A measurement method includes: an acceleration data acquisition step of acquiring acceleration data output from an accelerometer that observes an observation point of a structure when a moving body moves on the structure; a speed vibration component calculation step of calculating a first speed vibration component by performing integration processing and filter processing on an acceleration based on the acceleration data; and a displacement amplitude estimation step of estimating a displacement amplitude of the structure when the moving body moves on the structure based on an amplitude of the first speed vibration component and a conversion function calculated based on an approximate expression of deflection of the structure and environmental information including a dimension of the moving body, a dimension of the structure, and a position of the observation point, which are created in advance.

Systems and methods for determining mechanical properties of formation rock using, for example, millimeter-scale test samples of the formation rock are disclosed. The test samples may be single edge notched beam (SENB) test samples. The systems and methods may include performing laboratory testing on the SENB test samples and recording laboratory testing data obtained from the laboratory testing and performing a simulation on a numerical model of the SENB test samples and recording the simulation data obtained from the simulation. The laboratory testing data and the simulation data may be compared, and a determination may be made as to whether a selected degree of correlation is present between the laboratory testing data and the simulation exists. Mechanical properties of the formation rock are obtained from the simulation data when the selected degree of correlation exists between the laboratory testing data and the simulation data.

A cable tie having a strain sensing device incorporated therein. In one embodiment, the strain sensing device is a fiber Bragg grating (FBG), which is preferably molded within the strap. In this case, the cable tie further includes a socket in optical communication with the fiber Bragg grating for coupling of the cable tie to an external light source. In another embodiment, the strain sensing device is a mechanical fuse that activates in the presence of a predetermined amount of strain on the cable tie. The mechanical fuse is preferably disposed on the strap and is made of a fuse material having a mechanical strength lower than a mechanical strength of the material of the strap so that the mechanical fuse will fracture or deform earlier than the material of the underlying strap when both the fuse and the strap experience the same increasing strain.

A cable tie having a strain sensing device incorporated therein. In one embodiment, the strain sensing device is a fiber Bragg grating (FBG), which is preferably molded within the strap. In this case, the cable tie further includes a socket in optical communication with the fiber Bragg grating for coupling of the cable tie to an external light source. In another embodiment, the strain sensing device is a mechanical fuse that activates in the presence of a predetermined amount of strain on the cable tie. The mechanical fuse is preferably disposed on the strap and is made of a fuse material having a mechanical strength lower than a mechanical strength of the material of the strap so that the mechanical fuse will fracture or deform earlier than the material of the underlying strap when both the fuse and the strap experience the same increasing strain.

A system for detecting structural damage to a rigid structure, the system comprising: at least one impact generator capable of applying a one-time impact on the structure; an acoustic sensor; a vibration sensor; and a processing circuitry configured to: provide an indication of the structural damage to the rigid structure upon (a) a first deviation above a first threshold between an expected acoustic wave profile, expected to radiate from the structure, absent the structural damage, and an actual acoustic wave profile being measured by the acoustic sensor in response to an application of the one-time impact, or (b) a second deviation above a second threshold between an expected to vibration profile of expected vibrations of the structure, absent the structural damage, and an actual vibration profile in response to the application.

A system for monitoring a condition of a component of a well system located proximate to a seabed includes a first sensor assembly to couple to a telescopic joint coupled to an upper end of a riser, wherein the first sensor assembly is configured to measure at least one of a vibration, an inclination, and a strain in the riser, and a data processing system in signal communication with the first sensor assembly, wherein the data processing system is configured to estimate the condition of a subsea stack system based on measurements provided by the first sensor assembly.

One embodiment can provide a system for estimating useful life of a load-bearing structure. During operation, the system can perform a degradation measurement on the structure to obtain degradation data for a predetermined time interval, apply a constraint convex regression model to the degradation data, estimate a total useful life (TUL) of the structure based on outputs of the constraint convex regression model, and predicting a remaining useful life (RUL) based on the TUL and a current time.