Instrumentation and Measurement of Deformed Taylor Impact Projectiles

1
Instrumentation and Measurement of Deformed
Taylor Impact Projectiles
Goal Create an accurate and reliable measurement
system to analyze deformed, Taylor Impact Test
Projectiles.
Result Instrumentation can measure to an
accuracy of /- 0.00254 mm, in parallel
increments of 0.0194 mm.
ANDREW W. SIEFERT DR. DAHSIN
LIU Michigan State University
Limits of Existing Measurement Methods
Measure Non-Uniform Deformation
Motivation
As the design requirements for composite
structures continues to increase, more advanced
methods are required to predict and
experimentally verify composite behavior under
dynamic loading.
The projectile is rotated 15º for each captured
image to test for symmetric deformation

• Can Only measure features in as if they were
  symmetric about the projectiles longitudinal
  axis.
• Does Not Allow reliable incremented measurements
  of D as a function of Length D(L). (Literature
  Survey Best is 1 measure/0.5mm)
• Time Consuming and Prone to Human Error.

G.I. Taylor Impact Test
Velocity 200-300 m/s
Projectile Impact
Gas Gun
Dome Computer Software provides projectile
measurements along the longitudinal axis
Instrumentation
Undeformed Cylindrical Projectile
Rigid Target

• A cylindrical projectile is normally impacted
  into a rigid target resulting in a non-uniform
  deformation of the cylinder achieving strain
  rates of 104 to to 105 s-1.
• Measurements of the impacted cylinder are
• Used to verify shape profiles predicted by
  software simulated impact.
• Converted into constants used in Strength Models
  to compute the materials Dynamic Strength.

Diameter as a function of Length
Measure-ments can be graphed to provide a shape
profile to validate software predictions.
The mounted projectile interrupts the light beam
and casts a shadow onto the image plane where a
CCD camera captures the whole field image for
software analysis. Measurements are made by
correlating distance to variations in light
intensity created by the projectiles cast shadow.
Deformed Taylor Impact Projectile
Advantages of the Instrumentation

• Can Measure in increments of 0.0194 mm
• Test for Non-Uniform deformations
• Post analysis and Measurement takes approximately
  1 minute.

Light Source A Hg/White light projection source
was chosen (not shown). The projector eliminated
effects of laser speckle from the captured image
to improve the accuracy of the system.