A system for determining tension in a suspended rope includes an acceleration measuring device for measuring the acceleration of rope movement and an adapter for attaching the acceleration measuring device to the suspended rope. The system optionally includes a user device communicatively coupled to the acceleration measuring device. The user device computes rope tension based on the measured acceleration. The acceleration measuring device and user device can be combined into a single smart device. Examples of the system can accurately determine the tension in ropes used to suspend an elevator cabin, allowing a field technician to tighten the ropes to equal tension and to determine the weight of the cabin. In turn, a smoother and more secure operation of the elevator can be achieved.

An apparatus for orienting an accelerometer on a post-tensioned rod is provided. The apparatus includes a first open channel having a first sidewall forming a substantially half cylinder shape along at least a portion of a length of the first open channel, and a first axis along a length of the first open channel. The apparatus further includes a second open channel having a second sidewall forming a substantially half cylinder shape along at least a portion of a height of the second open channel, and a second axis along a height of the second open channel. The apparatus further includes a stopper wall having an inner surface disposed internal to a top end of the second channel. The inner surface of the stopper wall is substantially perpendicular to the second axis. The first axis is substantially perpendicular to the second axis. The first and second channels are contiguous.

A rod detensioning unit including a gripping unit removal device that engages a gripping unit on a rod, a chair frame configured to engage a rod, a rod tensioning unit that applies tension to an external portion of the rod to remove load from the gripping unit, a load cell unit that measures a tension level applied to the rod by the tensioning unit, a plate gripping unit that engages the rod and secures the chair frame, rod tensioning unit, load cell and plate gripping unit to the rod, a drive unit that engages the gripping unit removal device, and an extension unit affixed to the external portion of the rod when the original external rod length is too short to accommodate the de-tensioning unit.

An apparatus for emulating a variety of string instruments with a variety of configurations in order to measure the resulting, actual tension of a string on that instrument. The tension may be measured in real-time.

Sensor (1) for monitoring the parameters of rotation around its own axis and vibration of a steel rope (100), comprising a battery (2), indicator means (3) of the state of charge of said battery (2), at least a LED indicator (5), a power unit (7) which supplies the sensor (1), a detection unit (8) of the rotation angles (ϕ, γ) around its own axis (X) and of the vibrations of said steel rope (100), a microprocessor (9) for collection activity and data transmission, said sensor (1) being housed in a portion obtained in the core (110) of the steel rope (100).

A method of de-tensioning a rod by attaching a gripping unit removal device to a gripping unit and rod, positioning a chair frame over the gripping unit, positioning a rod tensioning unit along the rod with one end of the rod tensioning unit being in contact with the chair frame, applying a first force to the rod tensioning unit, positioning a bearing plate on the rod in contact with the rod tensioning unit, positioning a load cell in contact with the rod on the rod tensioning unit, securing a drive unit to the chair frame such that a portion of the drive unit is in contact with the rod, applying a second pressure to the rod tensioning unit, actuating the drive unit, and releasing the second pressure on the rod tensioning unit.

An apparatus for orienting an accelerometer on a post-tensioned rod is provided. The apparatus includes a first open channel having a first sidewall forming a substantially half cylinder shape along at least a portion of a length of the first open channel, and a first axis along a length of the first open channel. The apparatus further includes a second open channel having a second sidewall forming a substantially half cylinder shape along at least a portion of a height of the second open channel, and a second axis along a height of the second open channel. The apparatus further includes a stopper wall having an inner surface disposed internal to a top end of the second channel. The inner surface of the stopper wall is substantially perpendicular to the second axis. The first axis is substantially perpendicular to the second axis. The first and second channels are contiguous.

The present invention relates to a method for monitoring axial loads in structures by identifying natural frequencies. The analyzed structures are made up of elements connected by means of contact and are subjected to tractive loads, such as mooring lines. The proposed method uses bench testing and a computer model of the structure to determine the variation in the natural frequencies in relation to the variation in load. Monitoring is carried out using vibration sensors, in particular accelerometers, laser position sensors or strain gauges, to measure the dynamic behaviour of the structure, a data capture and signal conditioning unit and a computer to correlate the load applied and the vibration behaviour using a computer algorithm, and also to present the result. The invention discloses an easy calibration method for the dimensional template of the structures in question, high accuracy and easy installation and operation in the field.

The invention discloses a real-time online monitoring, perception, and early warning method for vortex-induced vibration of suspension bridges. Based on the fast Fourier transform FFT of the bridge acceleration monitoring signal, The first-order nature frequency of the bridge can be obtained by reading the horizontal coordinate corresponding to the first-order energy peak of the spectrum and determine the high-pass filter cut-off frequency. The low-frequency noise is eliminated by the filter in order to calculate the displacement of the bridge by the recursive acceleration integration method; Taking the integrated displacement data as the real part and its Hilbert transform as the imaginary part, the analytic signal is plotted and evaluated in the complex plane to achieve the perception and early warning of VIVs. The advantages of the invention are real-time, high precision, accuracy and intuition, online real-time VIV perception and measurement of bridge vibration parameters during VIV can be realized.

A method is provided for identifying or authenticating an object. The method includes vibrating the object at a plurality of frequencies. The vibrations from the object are sensed at each of the plurality of frequencies using an accelerometer. A vibration profile of the object is generated using the sensed vibrations. The generated vibration profile is then compared to a stored vibration profile. It is determined if the generated vibration profile matches the stored vibration profile. A match indicates that the object has been identified or authenticated. In another embodiment, an object capable of implementing the method is provided. In another embodiment, the object may include a replaceable accessary. In this case, the initial and generated vibration profiles may be created with the replacement accessary attached to the object. A match of the generated and initial vibration profiles indicates that the replaceable accessary is authentic.