OT- LUNA Blog-The Leading Edge – Observing Crack Strain with the FAA

http://lunainc.com/leading-edge-observing-crack-strain-faa/

Luna engineers were invited to the Federal Aviation Administration (FAA) William J. Hughes Technical Center in Atlantic City to participate in testing an aircraft fuselage panel. Several issues related to the structural integrity of fuselage applications are being examined using the Full-Scale Aircraft Structural Test Evaluation and Research Lab (FASTER), including the fatigue and damage tolerance characteristics of current and emerging metallic and composite designs, performance of bonded and mechanically fastened repair technologies, assessment of conventional and emerging non-destructive inspection, and more advanced structural heath monitoring methods.

Test panel being instrumented by Luna engineers. Two metal plates form patch repairs at previous crack test locations to remove any effects on current testing.

Luna engineers were able to showcase the ability of the ODiSI high-definition fiber optic sensing (HD-FOS) system to measure and map strain gradients in front of an intentional crack. The ODiSI’s measurements allowed the team to observe the strain gradients increasing at the crack front in real time as the panel was loaded biaxially in a load frame designed to replicate realistic flight load conditions.

Fiber Sensors in Front of the Crack

Straight fiber segments were laid 0.1 inches apart, perpendicular to the crack tip, in its path of propagation. This mimicked the layout of a 10-element strip strain gage sensor. Each straight section of fiber in front of the crack was approximately 2 cm in length, which is the equivalent of 30 strain gages per pass and over 300 sensors in total. Further to the right of the crack, engineers demonstrated the layout of a rosette configuration to obtain the principal strain magnitudes and directions.

Strain Gradient Peaks in Front of the Crack and Decays with Distance

The resultant strain along each fiber segment of interest at 3.7125 psi is shown as a color map of strain overlaid on a photo of the part.

Strain from the crack flows outward along its path in an arc with the highest strain occurring at the fiber nearest the crack edge. Colors indicate strain ranging from 0 to 1000 µε, note that closest to the crack measurements exceed 1000 µε.

Further details of the strain gradient profile can be seen more clearly in this plot of strain along each straight segment at four loads.

Strain is highest right in front of the crack and decays with distance away from the crack. As the panel was pressurized, the strain increased proportionally. The color scheme indicates proximity to the crack, red being closest and blue being the farthest.

The propagation of cracks can be slow at first, often taking weeks of accelerated loading before the part eventually violently fails. While the crack did not grow noticeably during Luna’s time at the FAA, the ability to detect and monitor the effects of flaws such as cracks with such a high spatial resolution and density makes HD-FOS a valuable tool for structural health monitoring.

OT-LUNA Blog-HD-FOS in Action this Week at Space Tech Expo

http://lunainc.com/hd-fos-action-week-space-tech-expo/

This week at Space Tech Expo in Pasadena, CA, we are showcasing our industry leading ODiSI 6100 measurement sensor for high-definition fiber optic sensing (HD-FOS).  We are highlighting the unique capabilities of the ODiSI 6100 by demonstrating the real-time acquisition of strain across the entire surface of a carbon fiber composite sample.  The composite sample was instrumented with a Luna HD strain sensor, a polyimide coated optical fiber calibrated for accurate strain measurements.  The 5m long HD fiber optic sensor was attached with epoxy to the interior surface of the composite sample, traversing the entire surface back and forth in order to get a full picture of strain across the entire component.  The surface has some tight curves which would be very difficult or impossible to instrument with traditional foil strain gages.

The screenshot below from the ODiSI 6100 software shows real-time strain from the attached sensor versus length.  The large periodic positive and negative peaks occur on sections of the sensor that are in line with the applied strain, while sections of the sensor running transverse to the applied strain show very low or zero strain.  This plot, taken with the ODiSI configured for a 1.3 mm gage pitch, is literally displaying nearly 4000 unique strain measurements along the length of the sensor.  This resolution can even be increased further by simply reconfiguring the ODiSI for a 0.65 mm gage pitch.

With dense data like this, alternative visualization of the data can be very useful. For example, the following visualization shows the measured strain data mapped to a 3D model of the composite component, indicating the intensity of the strain with color.

While you could have seen all this live and in person in Pasadena this week, there are plenty of other opportunities to see and learn how HD-FOS sensing and the ODiSI can deliver unprecedented resolution and visibility into your designs or processes.  You can learn more about the ODiSI 6100 measurement system here, or contact us to arrange a consultation with one of our engineers and see the ODiSI in action yourself.

OT-LUNA Blog-Luna Innovations Introduces New Multichannel ODiSI 6100

Expands Luna’s high-definition fiber optic sensing into manufacturing and multi-channel applications

http://lunainc.com/luna-innovations-introduces-multichannel-odisi-6100/

(ROANOKE, VA, December 12, 2017)  As the automotive and aerospace industries demand advanced measurement systems to enable lightweight designs, Luna Innovations Incorporated (NASDAQ: LUNA) launches its enhanced ODiSI 6100 proprietary strain and temperature measurement technology for integration into these industrial environments that place strict requirements on scalability, usability, interoperability, and overall system stability.

Unlike traditional electrical strain gages and thermocouples, the ODiSI 6100 Platform (Optical Distributed Sensor Interrogator) employs next generation fiber optic technology for distributed, multi-point, ultrahigh-definition profiling of strain and temperature.  ODiSI fiber optic sensors are small, lightweight and economical, enabling greatly reduced cost of sensor installation and the ability to embed sensors directly within materials and structures.

The enhancements included with the ODiSI 6100 strain and temperature measurement platform include minimized per-sensor cost, increased multi-channel capability, increased sensor length, increased speed of output, and real time 3-D data visualization software for computer model calibration.

“Automotive and aerospace R&D and manufacturing teams are incorporating composite and other lightweight materials into new designs at an increasing rate, requiring higher measurement performance in less time,” said Scott Graeff, president and chief executive officer of Luna Innovations. “Luna’s game-changing technology targets this need and addresses the major challenges faced by the aerospace and automotive industries as they incorporate new materials into modern designs.”

The customer feedback-driven ODiSI 6100 Platform now includes integrated, multi-channel capability up to 8 channels, millimeter resolution with up to 38,000 measurement points per channel, sensor length ranges from 2.5 m to 50 m per channel, a new, completely redesigned user interface with intuitive user controls operating on the Linux^TM operating system, and real-time data output at rates up to 250 Hz.  Optional 3-D Visualization Software allows strain and temperature data to be integrated seamlessly with CAD models and plotted and manipulated in three dimensions for the ultimate in computer-aided design. 

“ODiSI 6100 greatly enhances the engineer’s ability to maximize the performance of critical processes and next generation designs,” Graeff added. “ODiSI fiber optic sensors are small, nearly weightless and carry no electricity so they can go where electrical sensors cannot. With its high channel count, ODiSI 6100 replaces cumbersome and expensive strain gage data acquisition systems with a single, continuous, small form-factor sensor per channel. Because fiber optic sensors can also measure temperature, the ODiSI 6100 is also ideal for continuous, high-definition temperature profiling for industrial processes that rely on precise temperature control.”

Luna will be demonstrating the ODiSI 6100 at the CAMX tradeshow in Orlando, Florida this week in booth G79.  More information on the ODiSI 6100 including application case studies and product literature can be found here: http://lunainc.com/product/sensing-solutions/odisi-6100/

About Luna:

Luna Innovations Incorporated (www.lunainc.com) is a leader in optical technology, providing unique capabilities in high speed optoelectronics and high performance fiber optic test products for the telecommunications industry and distributed fiber optic sensing for the aerospace and automotive industries.  Luna is organized into two business segments, which work closely together to turn ideas into products: a Technology Development segment and a Products and Licensing segment. Luna’s business model is designed to accelerate the process of bringing new and innovative technologies to market.

Forward-Looking Statements:

The statements in this release that are not historical facts constitute “forward-looking statements” made pursuant to the safe harbor provision of the Private Securities Litigation Reform Act of 1995 that involve risks and uncertainties. These statements include the company’s expectations regarding the greater performance and new capabilities of the enhanced ODiSI platform, as well as Luna’s strategy to become the leading supplier of sensor testing for testing composites and other advanced materials. Management cautions the reader that these forward-looking statements are only predictions and are subject to a number of both known and unknown risks and uncertainties, and actual results may differ materially from those expressed or implied by these forward-looking statements as a result of a number of factors. These factors include, without limitation, failure of demand for the company’s products and services to meet expectations, technological challenges and those risks and uncertainties set forth in the company’s periodic reports and other filings with the Securities and Exchange Commission (“SEC”). Such filings are available on the SEC’s website at www.sec.gov and on the company’s website at www.lunainc.com. The statements made in this release are based on information available to the company as of the date of this release and Luna undertakes no obligation to update any of the forward-looking statements after the date of this release.

Investor Contact:

Dale Messick, CFO
Luna Innovations Incorporated
Phone: 1.540.769.8400
Email: IR@lunainc.com

OT-LUNA Innovations NEW Multichannel Sensing Platform-ODiSI 6100

 http://lunainc.com/product/sensing-solutions/odisi-6100/

NEW Multichannel Sensing Platform

We have launched a new multi-channel data acquisition system.  The ODiSI 6100  sensing platform can integrate into larger test management platforms collecting both strain and temperature data during critical tests.

 

Key Features

·                                 Multichannel measurements of strain-multiplex up to 200,000 measurement locations

·                                 Flexible, lightweight and easy to install sensors reduce time to first measurement

·                                 Passive, corrosion resistant, dielectric, flexible sensors go where other sensors can’t – in bends, around corners, embedded inside materials

·                                 Long sensor life – no drift or recalibration required, cycle counts >10⁷

·                                 Large strain range and high resolution allow for mapping of complex strain fields and large strain gradients

 

ODiSI 6100 Configuration Features

REAL-TIME STREAMING DATA

·                                 Stream measurements in real-time at the maximum measurement rate to a file or via TCP-IP to another computer

EASE OF INTEGRATION / EASE OF USE

·                                 Intuitive, easy to setup and use graphical user interface

·                                 IEEE 1588 PTP (Precision Time Protocol) synchronization

·                                 Json-based digital streaming data

·                                 Sync output TTL pulse

RELIABILITY

·                                 Continuous automatic optical alignment without user intervention

·                                 System and sensor health check ensures high data fidelity

TRACEABILITY

·                                 Optical frequencies validated every acquisition for accurate measurements

·                                 Strain sensors and associated coefficients calibrated with NIST traceable fixtures

3D VISUALIZATION SOFTWARE

·                                 Easily interpret and communicate complex data

·                                 Visualize large data files using contour and 3D mapping

·                                 Quickly focus on critical areas of interest in space and/or time

·                                 Visualize and share ODiSI data mapped on imported .stf files