SAND SAMPLING APPARATUS

Eglin Air Force BaseGina TeofilakRichard KlimasDan MortensenRuben De Sousa

William “Bill” Cooper, MSgt Wes Schuler,LT Brad Breaux, Lalit Chhabildas

AFRL/RWMunitions Directorate

Air Force Research Laboratory

Phil MetzgerGranular Mechanics & Surface Systems Lab

NASA, Kennedy Space Center

Victor GiurgiutiuAir Force Office of Scientific Research

Sand Fracture Mechanisms During High-Speed Sand Impacts

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Overview- The Experiment

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Target filled with 3000 lbs. sandProjectile shot through the targetDocumentation of virgin & impacted sand grain morphology

IntroductionIN

TROD

UCTIO

N

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Fractured sand

Projectile

Target shot line

Current Design

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Driven by a chain

Steel rod with supports (x-axis)

Actuators with threaded rods (y & z axes)

3 motors automated

Control system

Z

X

Y

EGLIN

VISIT 10/31/2008Current Design Cont’d.

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Fabrication

- CNC to fabricate end plates and bearing holders- Mill to construct side plates and lead screw nut- Lathe to turn down lead screws and support rods

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Actuators

- Y and Z actuators same concept, but different sizes

- Same spacing between stabilizer rods and lead screw- Y actuator is 24in x 8in- Z actuator is 17in x 8in

-Z actuator mounted vertically onto the horizontally mounted y actuator

- Bearing holders and lead screw nut were precisely fabricated to prevent binding and torque forces

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Remaining Fabrication

Two 8ft rails with supports every 1ft (x axis)

Various parts that attach the y actuator to x axis: clamp for the chain end supports that will house the pulleys for the chain

Group will be going down to Clearwater this weekend to fabricate these parts, and create a base to mount the apparatus for experimentation

Required Torque Needed (oz*in)X movement 20Y movement 40Z movement 20

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Using encoders and servo controllers to do motion control

Became expensive - >$200 per motor

Wall Socket Power Supply Microprocessor

Encoder

Encoder

Encoder

Motor

Motor Controller – Servo Controller

Motor

Motor

X Direction Movement

Z Direction Movement

Y Direction Movement

Electronics- Old Method

Motor Controller – Servo Controller

Motor Controller – Servo Controller

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Electronics- New Method

Using switches and hard coding to get motion control desired.

Cheaper but more time consuming.

Wall Socket Power Supply Microprocessor

Switches

Switches

Switches

Motor Controller Motor

Motor Controller

Motor Controller

Motor

Motor

X Direction Movement

Z Direction Movement

Y Direction Movement

Cabling ran close to the mechanism in twisted pairs and attached away from moving parts.

Electronics are being enclosed in a plastic enclosure for protection from the environments.

REFERENCES1. Cooper, William “Bill”, MSgt Wes Schuler, AFRL/RW

Munitions DirectorateAir Force Research Laboratory

2. Mortensen, Charles, Owner, Dynatech Associates

3. Dr. Chiang Shih, FAMU-FSU College of Engineering, Mechanical

4. Dr. Daudi Waryoba, FAMU-FSU College of Engineering, Mechanical

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