Processing and Characterization of Polycrystalline YAG (Yttrium Aluminum Garnet) Core-Clad Fibers

New techniques could make polycrystalline YAG suitable for use in fiber lasers.YAG-based fiber lasers could offer efficient operation at power levels beyond those achievable in current state-of-the-art silica-based fiber lasers if losses can be minimized. To address this, researchers have investigated creating both single-crystal and polycrystalline YAG fibers. Among the cases reported is the preparation of single-crystal YAG fibers using laser heated pedestal growth (LHPG), which resulted in fiber diameters of 400 μm and optical losses around 1–2 dB/m in the 1–3 μm wavelength range. Single-crystal YAG fibers with diameters of ~ 30 μm have even been reported.

Posted in: Briefs, TSP, Aerospace, Defense, Materials, Finite element analysis, Fiber optics, Lasers, Materials identification


Multi-Scale Analysis of Deformation and Failure in Polycrystalline Titanium Alloys Under High Strain Rates

Developing a crystal plasticity-based computational modeling tool for predicting performance.Extensive use of titanium alloys in critical industrial and military applications, such as compressor blades of jet engines and armor of ground combat vehicles, has motivated researchers to understand, measure and tailor the mechanical properties of these alloys over a wide range of strain rates and temperatures. Of special interest has been the mechanical response of these alloys under high rates of deformation and failure under cyclic/dwell fatigue.

Posted in: Briefs, TSP, Aerospace, Defense, Materials, Aircraft structures, Body panels, Failure modes and effects analysis, Materials properties, Titanium alloys, Military vehicles and equipment


Abrasion Testing of Products Containing Nanomaterials

Ensuring repeatable results when capturing and analyzing released particles.This SOP describes how to detect and quantify the release of nanoparticles from surface coatings into the air using a mechanical process that employs abrasion to simulate sanding. A material containing nanoparticles will be physically abraded and the materials released will be collected in a custom abrasion testing system. They will then be characterized by different methods such as Scanning Electron Microscopy (SEM) or Transmission Electron Microscopy (TEM) and other methods.

Posted in: Briefs, TSP, Aerospace, Defense, Materials, Microscopy, Nanomaterials, Wear, Test procedures


Spectrum Fatigue of 7075-T651 Aluminum Alloy Under Overloading and Underloading

Most structural members and machine components are subjected in service to cyclic loadings of varying amplitude. The variation in stress level follows either a regular or random pattern. The resulting crack growth is affected by the applied load sequence in the early stage (crack initiation) and in the later stage (crack propagation) of fatigue. The fatigue crack growth is known to be retarded by tensile overloads and accelerated by compressive overloads (underloads). However, the phenomenon and mechanism of the load sequence effects, especially those of overloading and underloading, on fatigue crack growth in different environments remain to be clarified.

Posted in: Briefs, TSP, Aerospace, Defense, Materials, Failure modes and effects analysis, Aluminum alloys, Fatigue


Automakers Use 3D Printing to Reap Benefits of Lower-Cost Tooling and More Efficient Assembly

3D printing, also known as additive manufacturing, has existed since the 1980s, but has recently been more widely adopted. In the span of a decade, 3D printers have moved from an optional piece of equipment for producing relatively simple prototypes, to an absolute necessity — one that is transforming the automotive industry in fundamental ways, This white paper highlights 3D printing applications in automotive today, and what’s coming tomorrow.

Posted in: White Papers, White Papers, Automotive, Manufacturing & Prototyping


New Web-Based Software Enables Quick Drone Design

Doug Hunsaker (right) has created a free, online 3D software for the design of safe and efficient small autonomous vehicles. A Utah State University aerospace engineer is offering the public a free software tool that could revolutionize the drone industry. Doug Hunsaker, an assistant professor of mechanical and aerospace engineering at USU, is offering a 3D online software program that generates aerodynamic information about a user’s aircraft design.

Posted in: News, Aerospace, Defense, Computer-Aided Design (CAD)


New Ice-Repellant Material Could Improve Aviation Safety

A drop of water rolls off the MAGSS ice-phobic surface. (Cullen College of Engineering) Icy conditions can be deadly when flying into bad weather. Researchers at the University of Houston have discovered a material that can be applied to any surface to repel ice. The material, known as a magnetic slippery surface (MAGSS), could be applied to aircraft wings.

Posted in: News, Aerospace, Defense, Coatings & Adhesives, Materials