A surface mounted monitoring system is disclosed that is useful for detecting the presence of both ordinary and excessive loads on a surface, and for providing real-time or near real-time trending data. The system includes an array of force transducers disposed on the exterior surface of a structural member such as a roof. In an exemplary embodiment, transducers may be placed on an interior surface, such as embedded within insulation. The force transducers detect the magnitude of a load force acting on the surface. A data analysis module (DAM) may record force readings in a circular memory buffer, so that recent data can be recovered in the event of a catastrophic collapse. The DAM may also communicate with a monitoring device that can display real-time loading data to a user and perform other analysis.

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.

In an optical fiber monitoring system which detects physical disturbance or other parameters such as temperature or strain of a fiber where a monitor signal is transmitted along the optical fiber and analyzed to detect changes which are indicative of an event, a method is provided for periodically checking proper operation of the optical fiber monitoring system. A fiber disturbance actuator periodically causes a pattern of disturbances of a portion of the fiber at a predetermined location thereon where the disturbance is characteristic of the event to be monitored. The monitor signal is analyzed to detect the pattern of changes and in the event that expected changes are not detected, a warning is issued that the intrusion detection system is not properly operating.

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 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.

The method allows to monitor a composite material comprising an epoxy resin tilled with electrically conductive nanoparticles, wherein at least one electrical property i.e. impedance of the composite material is influenced by being subjected to a mechanical deformation. The method provides for inserting the composite material in an electric circuit emitting an electric signal whose value depends on the electrical property, so that, when the value of the signal overcomes a given threshold value, a warning message is delivered.

A sensor system provides measurement of building interstory drift based on a laser beam impinging on a discrete diode sensor array. The diode sensor array determines the location at which a projected laser bean strikes the array, which provides a direct measurement of interstory drift. The diode sensor array is a two dimensional array of discrete diodes that allow the location of an impinging laser beam to be very accurately tracked as the beam moves back-and-forth across the diode array. Local rotations of the laser source that result from rotations of structural members (e.g. floor beam rotation) are appropriately corrected for. This allows accurate, dynamic measurements of the interstory drift between two floor levels of a shaking building.

A load sensing system for sensing a load on a structure can include an optical load sensing element configured to change an optical state based on a force applied thereto, an optical source operatively connected to the optical load sensing element and configured to input an input optical signal to the optical load element, and an optical detector configured to receive a returned optical signal from the optical load sensing element. The optical detector can be configured to detect one or more frequency peaks of the returned optical signal and to use the one or more frequency peaks of the returned optical signal to correlate to a load value of the load and output the load value indicative of the load.

The present disclosure is directed to a method for estimating tower loads, such as tower deflection, of a wind turbine. The method includes receiving an estimate of slow variations in thrust of a tower of the wind turbine. The method also includes determining, via one or more sensors, tower accelerations of the tower of the wind turbine. Thus, the method also includes estimating the tower loads of the wind turbine as a function of the estimate of slow variations in thrust of the tower and the tower accelerations.

A carbon nanofiber aggregate (CNFA) system and method provides self-sensing capabilities that can be used to detect strain, moisture, and temperature changes. The CNFA may include cement, aggregate, silica fume, high-range water reducer (HRWR), and/or carbon nanofibers. The metal meshes in the CNFA may be utilized to monitor the electric properties of the CNFA to detect strain, moisture, and temperature changes. The CNFA may be embedded in concrete structures to allow detection of strain, moisture, and temperature changes that may cause damage to structures. Several metal meshes may be embedded in the CNFA.