Determining Applied Load Data with Strain Measurements

Determining Applied Load Data with

Strain Measurements

Armstrong researchers have developed a method for obtaining externally applied, out-of-plane operational load data on complex structures using surface in-plane strain measurements. This approach allows for efficient characterization of out-of-plane bending and torsional stiffness of structures.

Currently, industry uses computational methods such as finite element analysis (FEA) to obtain operational load data for complex structures; however, this approach is time consuming and requires the structure to be broken down into small elements for analysis, a challenging task for structures with complex geometries. To obtain real-time load data,

standard methods rely on the use of strain gauges on the structure, yet a costly and extensive calibration process must be performed prior to real-time analysis. This Armstrong-developed method saves time and is more efficient and accurate.

Benefits

 Provides real-time data: Enables measurements outside test facilities and during operation

 Less expensive: Provides similar spatial resolution to that obtained from the more cumbersome, labor-intensive, and costly FEAs

 More accurate: Improves accuracy of the simplified structural models

Applications

      Aircraft wing analysis

      Structural health monitoring for buildings, bridges, and ships

 Fiber Optic Sensing

Armstrong's portfolio of Fiber Optic Sensing System (FOSS) technologies offers unparalleled options for high-resolution sensing in applications that require a unique combination of high-powered processing and lightweight, flexible, and robust sensors. The system measures real-time strain, which can be used to determine two-dimensional and three-dimensional shape, temperature, liquid level, pressure, and loads, alone or in combination. Initially developed to monitor aircraft structures in flight, the system's capabilities open up myriad new applications for fiber optics-not just in aerospace but also for civil structures, transportation, oil and gas, medical, and many more industries.

The Armstrong approach employs fiber Bragg grating (FBG) sensors, optical frequency domain reflectometry (OFDR) sensing, and ultra-efficient algo-rithms (100 samples/second). Engineers are continually seeking new ways of looking at information and determining what is important. Armstrong's FOSS technologies focus on critical research needs. Whether it is used to determine shape, stress, temperature, pressure, strength, operational load, or liquid level, this technology offers ultra-fast, reliable measurements.