Fiber Bragg Grating Strain Sensors for Creating Modern Sophisticated Equipment

Strain measurement is imperative during prototype design and testing. Strain measurements ensure that materials perform as they should and that the equipment is safe and durable. Measuring strain is crucial for testing complex structures, like aircraft, turbines, etc. There multiple ways in which stress can be measured. However, it is widely accepted that FBG sensors are the most efficient way of strain measurement. FBG sensors provide multiple advantages over other methods:

1) high sensitivity;

2) small size;

3) ability to be mounted on any surface;

4) immunity to electromagnetic interference;

5) reliability even in harsh environments;

6) low sensitivity to vibration and heat.

FBG strain sensors are used in wing load testing to determine the structure’s performance and possible limitations under the lifting forces during flight. There are several benefits that FBG strain sensors offer to the aerospace field for this type of application. For instance, FBG technology provides strain measurement using a big number of continuous sensors which ensures maximum coverage from a single optical fiber. The immunity to electromagnetic interference, radio frequency interference and other electrical influences makes FBG strain sensors ideal for use in hazardous environments, such as flight. Also, FBG sensors are less cumbersome to install. In addition, the FBG strain sensor prices are expected to decrease by 20% which will open up new opportunities for various markets.

The repeated loading and unloading of a material causes fatigue. It is estimated that around 90% of structural failures are a result of fatigue. To determine the breaking point of a structure, fatigue tests are performed. The tests indicate the number of loading cycles until failure. FBG sensors are able to provide real-time data on strain fields and load distributions. The immunity to both low and high temperatures enables the sensors to be monitored during the high-temperature cure phase of composite fabrication. The fatigue life of an FBG strain sensor far surpasses that of other methods of strain measurement.

The tendency to build longer wind turbines with longer blades complicates the maintenance. The design of stronger, lighter materials is necessary, however small imperfections during the manufacturing process can cause failures. FBG strain sensors may provide real-time knowledge of load distributions and turbine blade shape. This data will provide valuable information on the needed adjustments to the blades manufacturing.

Optromix, Inc. is a U.S. manufacturer of innovative fiber optic products for the global market, based in Cambridge, MA. Our team always strives to provide the most technologically advanced fiber optic solutions for our clients. Our main goal is to deliver the best quality fiber optic products to our clients. We produce a wide range of fiber optic devices, including our cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Optromix, Inc. is a top choice among the manufacturers of fiber Bragg grating monitoring systems.

If you have any questions, please contact us at info@optromix.com

 

 

Development of Fiber Bragg Grating Sensors for Aircraft Structural Health Monitoring

FBG sensors for aircraft monitoringThe use of composite materials in modern aircraft has been growing because of the numerous advantages that they provide. Generally, composite materials are less sensitive to corrosion, have enhanced fatigue behavior, and higher specific mechanical properties when compared to traditional materials used in aerospace applications. By contrast, composite materials have problems with damage detection which is an important procedure in the air transport industry. The main issue that occurs during the process of use is the separation of laminae from each other which happens on the inside of the material and is hidden from the outside. Nondestructive methods of aircraft testing are not effective enough for material monitoring.

Structural health monitoring consists of placing measuring and sensing devices on a structure to record, localize, analyze, and eventually predict damage. Most structural health monitoring techniques strive to measure the needed data in a non-destructive way. Fiber Bragg grating sensors are optimal for measuring different variables as they are more cost-efficient, easy to implement on most surfaces, including composite materials.

Aircraft structures require regular, scheduled inspections and monitoring of all possible hazards due to their special conditions and the principles of their design. Therefore, structural health monitoring is conducted through fiber optic devices and has great potential to reduce the costs related to these operations. Fiber Bragg grating sensors have proved to constitute the most promising technology in this field. In order to prolong the operation period of all kinds of complex engineering systems and avoid catastrophic failures, so it is necessary to achieve the highest levels of damage detection. The automation of the inspection process is a point of major importance to reduce inspection efforts. The structural health monitoring system on the basis of fiber optic products can be defined as a set of devices that provide information that allows us to locate, evaluate, and predict the loading and damage conditions of a structure. The structural health monitoring of aircraft structures can conduct real-time checks, reducing costs, and improving the reliability and performance of the structures. A wide range of potential structural health monitoring technologies is being developed to meet these needs, and the most promising options are:

  • electrical strain gauges and crack wires
  • acoustic emissions methods
  • optical-based technologies
  • comparative vacuum monitoring
  • microelectromechanical systems (MEMS)

Fiber optic products and fiber optic devices, in general, are very appropriate to perform structural health monitoring due to the fact that they have their intrinsic capabilities, such as sensitivity to electromagnetic radiation, low weight, compact size, great sensitivity and resolution, and their suitability to be embedded into structures. Fiber optic devices for monitoring the strain in aircraft structures can be classified into the following categories: intensity-based, interferometric, distributed, and grating-based fiber optic devices.

Among grating-based sensors, FBGs and probably the most mature and widely employed optical sensors for structural health monitoring of engineering structures due to their fast development achieved in recent years.

Optromix is a fast-growing vendor of fiber Bragg grating (FBG) products line: fiber Bragg grating sensors, FBG interrogators and multiplexers, distributed temperature sensing (DTS) systems. We create and supply a broad variety of top-notch fiber optic solutions for the monitoring of various facilities all over the world.

If you are interested in Optromix FBG sensors, please contact us at info@optromix.com

Magnetic Sensors Based on Fiber Optic Products Detect Very Weak Magnetic Fields

magnetic FBG sensorsA light-based technique for measuring very weak magnetic fields was recently developed by researchers at the University of Arizona. A portable, low-cost brain imaging system based on fiber optic products can operate at room temperature in unshielded environments. This fiber optic system would allow real-time brain activity mapping after potential concussions on the sports field and in conflict zones where the effect of explosives on the brain can be catastrophic.

Speaking specifically, scientists and engineers fabricated the magnetic sensors using optical fibers and a polymer-nanoparticle composite that is sensitive to magnetic fields. The researchers selected for their project nanoparticles based on magnetite and cobalt. These materials exhibit very high magnetic sensitivity. The aforementioned magnetic sensors can detect the brain’s magnetic field, which is 100 million times weaker than the magnetic field of Earth. Also, the researchers showed that new magnetic sensors can catch the weak magnetic pattern of a human heartbeat and has the capability to detect magnetic fluctuations that change every microsecond from an area as small as 100 square microns. Multiple seasons could then be used together to provide high spatial resolution brain mapping.

During work, the polarization rotation using an optical interferometer was detected. This works by splitting laser light into two paths, one of which passes through the highly-sensitive material while the other does not.

Indeed, further development of the researchers will be aimed at the long-term stability of magnetic sensors. Scientists plan to study how well sensors withstand environmental changes. Plus they want to fabricate several hundred sensors to make a special fiber optic system for evaluating and imaging the entire magnetic field of a human brain.

The newly developed magnetic sensors could help scientists better understand the activity of the brain and diseases of the brain such as dementia and Alzheimer’s. They might also be used to predict volcanic eruptions and earthquakes, identify oil and minerals for excavation, and detect military submarines. In addition to this, such magnetic sensors could offer an alternative to the magnetic reasonable imaging (MRI) systems currently used to map brain activity without the expensive cooling or electromagnetic shielding required by MRI machines.

Optromix is a fast-growing seller of such products from the fiber Bragg grating (FBG) line of products: fiber Bragg grating sensors, FBG interrogators, and multiplexers and, of course, Distributed Temperature, Acoustic, and Strain Sensing systems (DTS). Our major goal is to deliver the best quality of fiber optic sensors to our clients. Optromix creates and supplies a broad variety of excellent fiber-optic solutions for the monitoring of various facilities all over the world.

If you are interested in Optromix fiber optic products, please contact us at info@optromix.com

 

 

Fiber Optics in Avionics: Optical Fiber vs. Copper Cable

FBGs in avionicsFiber optic technology is revolutionizing the avionics systems and is lightly to be the ideal solution to future aircraft requirements. Fiber optic products are revolutionizing the avionics systems and ideally to be the perfect solution to future requirements. A modern jet has enormous amounts of data flowing through it to support the latest technologies in the cockpit and the cabin. All that data has to be delivered at lightning speed. This necessity has led aircraft manufacturers and airlines to turn to the optical fiber. The copper cables co-existed with fiber optic applications for decades. Currently, designers and engineers find fiber optic products to make better sense technically and economically in the overwhelming majority of cases.

The ability of the optical fiber to transmit much more information in less time over longer distances than traditional copper wire has become the reason that fiber optic equipment is being deployed on aircraft. There are fiber optic bundles of copper cables in an aircraft and the signals which they carry are fully replaceable by fiber optic products to allow an improvement of the system in various different ways.

There are two common trends regarding data transmission in the avionics market: constantly growing transmission speeds and the need to reduce weight. Fiber optic systems are an ideal response to these two trends in providing for high-speed data and immunity to electromagnetic interference that eliminates the need for any type of screening which can often be very expensive due to their weight and complexity. Fiber optic equipment offers lower wastage, weight, size, etc. These advantages make fiber optic equipment suitable for application in aircraft where space restrictions and electromagnetic interferences could be detrimental.

Nowadays fiber optic systems have been implemented in different aircraft systems such as sensory systems, distributed opening systems, and fiber optic aircraft monitoring.

In addition to this, fiber optic devices applied to the monitoring of aircraft structures provide some advantages over traditional devices. Fiber Bragg grating sensors have proved to constitute the most promising technology in this field. In order to prolong the operation period of all kinds of complex engineering systems and avoid catastrophic failures, so it is necessary to achieve the highest levels of damage detection. The automation of the inspection process is a point of major importance to reduce inspection efforts. The structural health monitoring system on the basis of fiber optic products can be defined as a set of devices that provide information that allows us to locate, evaluate, and predict the loading and damage conditions of a structure. The structural health monitoring of aircraft structures can conduct real-time checks, reducing costs, and improving the reliability and performance of the structures. A wide range of potential structural health monitoring technologies is being developed to meet these needs, and the most promising options are:

  • electrical strain gauges and crack wires;
  • acoustic emissions methods;
  • optical-based technologies;
  • comparative vacuum monitoring;
  • microelectromechanical systems (MEMS).

Fiber optic products and fiber optic devices, in general, are very appropriate to perform structural health monitoring due to the fact that they have their intrinsic capabilities, such as sensitivity to electromagnetic radiation, low weight, compact size, great sensitivity and resolution, and their suitability to be embedded into structures. Fiber optic devices for monitoring the strain in aircraft structures can be classified into the following categories: intensity-based, interferometric, distributed, and grating-based fiber optic devices.

Among grating-based sensors, FBGs and probably the most mature and widely employed optical sensors for structural health monitoring of engineering structures due to their fast development achieved in recent years. Fiber Bragg grating sensors have important advantages over conventional strain sensors:

  • high sensitivity and resolution, low weight and small size, the absence of the electromagnetic interference;
  • suitability for being attached to a structure or embedded in composite materials
  • high multiplexing capability;
  • wavelength-encoded sensing in a way that is totally independent of the optical intensity;
  • different magnitudes can be measured using FBGs, such as strain, temperature, vibration, or humidity.

Optromix, Inc. is a U.S. manufacturer of innovative fiber optic products for the global market, based in Cambridge, MA. Our team always strives to provide the most technologically advanced fiber optic solutions for our clients. Our main goal is to deliver the best quality fiber optic products to our clients. We produce a wide range of fiber optic devices, including our cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Optromix, Inc. is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com