Accession Number:

AD1122711

Title:

High-Speed, Real-Time Infrared Imaging of Hot Spots in Reactive Materials: Dynamic Experiments and 3D Modeling

Descriptive Note:

[Technical Report, Final Report]

Corporate Author:

Brown University

Personal Author(s):

• Guduru, Pradeep
• Malhotra, Pinkesh
• Jiao, Tong
• Clifton, Rodney J.

Report Date:

2021-02-05

Pagination or Media Count:

48

Abstract:

This project consists of two components i design and development of a high speed infrared imaging system and ii pressure-shear plate impact experiments on energetic materials or their simulants. The eventual objective is to combine i and ii to visualize hot spot evolution in energetic materials under well-defined plane wave loading conditions. Under task i, we have designed and built a unique high speed infrared imaging system to image temperature fields associated with hotspot evolution in energetic materials under high rate deformation. The system consists of a 24x24 array of HgCdTe detectors that constitutes the focal plane array. We have designed a fan-out chip that provides individual access to each pixel, a flexible printed circuit board to carry the signals to outside the dewar for signal processing, custom optics for diffraction limited imaging and a high speed data-acquisition to acquire images at up to a million frames per second. The progress report on the status of this effort is reported separately. Pressure-shear plate impact PSPI experiments were conducted to study the mechanical behavior of HTPB binder and sucrose energetic material simulant at high strain rates and high pressures. The main finding of these experiments is that, although HTPB is a soft elastomer at ambient conditions, its shear strength can be as high as 0.5 GPa under a pressure of about 9 GPa and a strain rate of 0.4 x 106 1s. At similar pressures and shearing rates, PSPI experiments on sucrose--a simulant for energetic crystals--show a shearing resistance of 288 MPa. In these experiments, sucrose exhibits pronounced strain softening, even a dramatic drop in shearing resistance at large shear strains. Pressure-shear plate impact experiments have also been conducted on HTPB-sucrose composite specimens as well.

Descriptors:

• materials science
• modulus of elasticity
• specific heat
• chemical reactions
• explosives
• mechanics
• detectors
• energetic materials
• materials
• shear stresses
• composite materials
• equations
• hydroxyl terminated polybutadiene
• molecules
• phase transformations
• polymers
• shear bands
• shear modulus
• thermal expansion
• computational modeling

Subject Categories:

• Optics

Distribution Statement:

[A, Approved For Public Release]