Fuzing„s Evolving Role in Smart Weapons€¦ · © Fraunhofer EMI 8 10.000 g 3.300 ms (exp) 20.000 g 1.250 ms (exp) 30.000 g 0.800 ms (exp) 40.000 g 0.520 ms (exp) 50.000 g 0.350

© Fraunhofer EMI

55th Annual Fuze Conference

Fuzing„s Evolving Role in Smart Weapons

Generation and Measurement of

Long Duration High-g Acceleration Profiles

S. Nau,

V. Aust, N. Pilous

Fraunhofer Ernst-Mach-Institut

Salt Lake City, May 26th 2011

© Fraunhofer EMI 2

Introduction

Need for Test Methods

Generation of Long Duration Transients

EMI Defined-Long-Duration Shock Test

Application

Choice and Test of Electronic Components

Measurement of Long Duration High g-Acceleration Profiles “g-rec”

Penetration of Concrete

Summary

OUTLINE

© Fraunhofer EMI 3

Motivation

Smart Weapons with Penetration Capability

High-g hardened fuzing

Large warheads

Upcoming: Smaller calibers

as for precision guided munitions

with moderate effect

a max > 100,000 g

the smaller the ammunition,

the bigger the acceleration

No manufacturers specifications available

for electronic parts for high-g-regime

Inexplicable system failures in the field

need for reliable, cheap high-g-test methodology

© EMI

image: wikipedia

© Fraunhofer EMI 4

Required Test Methodologies for

Sub-Scale Survivability Test

Fuze-Conference 2010:

D. Hayles, DTRA : Notional Shock Spectrum

technical requirement:

v0, DUT > 100 m/s

© Fraunhofer EMI 5

EMI Defined-Long-Duration (DLD) Shock Test

High initial velocity of actuator

long duration and high amplitude load profiles

Numerically tailored compression body

quantitative load profile estimation

new load regimes reproducible accessible

Experimental validation by g-rec or PDV* measurements

a [g

]

t [ms]

measurement

50 kHz filtered

Example: 30.000 g, 800 µs

- Numerical prediction:

movement of center of gravity

- Measurement inside sample holder

* PDV: Photonic Doppler Velocimetry

© EMI

© Fraunhofer EMI 6

Current R&D-setup:

m(Device Under Test) up to 200 g

ø < 34 mm,

l = 100 mm

If needed: Device under Test electrically connected

Low temperature experiments (-46 °C) possible

Modest cost

Extension to spinning systems is under way

Exemplary sample holder Example: 80.000 g oscillator-Test

} scalable to higher values

© EMI © EMI

EMI Defined-Long-Duration (DLD) Shock Test

a [g]

oscill

ato

r-sig

nal [V

]

© Fraunhofer EMI 7

EMI - DLD - Shock Test

0,0 0,5 1,0 1,5 2,0 2,5 3,0

-90000

-80000

-70000

-60000

-50000

-40000

-30000

-20000

-10000

0

a [g

]

t [ms]

Num. Simulations

10.000 g

20.000 g

30.000 g

40.000 g

50.000 g

60.000 g

80.000 g© EMI

0,0 0,5 1,0 1,5-80000

-70000

-60000

-50000

-40000

-30000

-20000

-10000

0

0,0 0,5 1,0 1,5-40000

-30000

-20000

-10000

0

t [ms]

a [g

] a

[g

]

Comparison

- Experimental Data (50 kHz filtered)

- Numerical Simulation

20.000 g

60.000 g

t [ms]

© EMI

© EMI

- movement of

center of gravity

© Fraunhofer EMI 8

10.000 g 3.300 ms (exp)

20.000 g 1.250 ms (exp)

30.000 g 0.800 ms (exp)

40.000 g 0.520 ms (exp)

50.000 g 0.350 ms (sim)

60.000 g 0.310 ms (exp)

80.000 g 0.025 ms (exp)

0.300 ms (sim)

EMI-DLD-Experiments

Experiments validated by

- exp acceleration measurement or

Photonic Doppler Velocimetry

- sim numerical Simulation and

high-speed Video

Experiments were conducted in

cooperation with industry partners

and used for product development.

D. Hayles, DTRA, Fuze Conference 2010

EMI - DLD - Shock Test Experimental Results

© Fraunhofer EMI 9

Device behavior upon high-g-loads:

Intended function

Disintegration of the device

Malfunction only during load

Example: Capacitor 1

intended function

DLD-Shock-Test with

electrical access to relevant

device properties during load Time [ms]

Acce

lera

tio

n [g

]

U [

V]

capacitor 1

© EMI

Application Choice and Test of Electronic Devices

© Fraunhofer EMI 10

Device behavior upon high-g-loads:

Intended function

Disintegration of the device

Malfunction only during load

Example: Capacitor 2

- (Reversible) effect only during load !

- Pre- and post-mortem results could

be misleading

Approach / solution :

Usage of different devices,

or device technologies

Improved engineering concepts

0 2 4 6 8 10 12 14 16 18 20

-20000

-10000

0

10000

20000

30000

40000

50000

-0,5

0,0

0,5

1,0

1,5

2,0

2,5

3,0

Be

sch

leu

nig

un

g in

GZeit in ms

Pendelversuch 10

Diffe

ren

zsp

g. in

V

DLD-Shock-Test with

electrical access to relevant

device properties during load Time [ms]

Acce

lera

tio

n [g

]

(Vo

lta

ge

with load –

Vo

lta

ge

w/o

load)

[V] capacitor 2

© EMI

Application Choice and Test of Electronic Devices


Autonomous digital data recorder with shock accelerometer

Resistant to high accelerations and decelerations ( > 100,000 g, Ver. a)

PC based data retrieval after projectile recovery

modular

assembly: Bridge

Sensor

Recorder

Electronics Batteries

Plug connector

data extraction

Concept

2 versions: a) hard-wired version ø = 26 mm, l = 155 mm

b) programmable, based on microcontroller ø = 23 mm, l = 80 mm

Ver. a © EMI

Application g-rec Measurement of Long Duration High-g Acceleration Profiles


Ver. b

ø = 23 mm

Investigation of penetration processes

Movement of the center of gravity

Characterization of mechanical properties

of HE during impact conditions

Stand alone data recorder for harsh environments

Measurement tool for fuze systems during impact

Investigation of interior dynamic of penetrators

Study of mechanical wave propagation and resonances

Damage mechanisms, …

v0

a(t)

0,0 0,5 1,0 1,5 2,0 2,5

-50000

-25000

0

25000

Simulation: "g-rec 32mm geschottetes Ziel 03.si3"

Time [ms]

Acce

lera

tio

n [g

]

© EMI

200 kHz filtered

Application g-rec Measurement of Long Duration High-g Acceleration Profiles


36 mm - penetrator equipped with g-rec:

Gun launch (powder cannon) v0 = 600 m/s

© EMI

© EMI

Application Concrete Penetration Measurement of Long Duration High-g Acceleration Profiles


10 11 12

-150

-100

-50

0

50

Acce

lera

tio

n [

10

00

g]

Time [ms]

impact

v0 = 600 m/s

raw data

10 kHz filter

Time [ms]

Acce

lera

tio

n [1

00

0 g

]

© EMI

© EMI



Projectile and sabot,

projectile: cal. 60 mm

150 mm-Facility,

Ernst-Mach-Institute, Germany

© EMI

© EMI


Experiments with 60 mm projectiles


caliber: 36 mm

10 11 12

-150

-100

-50

0

50

Acce

lera

tio

n [

10

00

g]

Time [ms]

impact

v0 = 600 m/s

raw data

10 kHz filter

Time [ms]

Acce

lera

tio

n [1

00

0 g

]

© EMI

0 1

-150

-100

-50

0

50

Acce

lera

tio

n [

10

00

g]

Time [ms]

impact

raw data

10 kHz filter

© EMI

Acce

lera

tio

n [1

00

0 g

]

caliber: 60 mm

Interpretation after experiment, no real time processing.


amax, 36 mm more than two times higher than amax, 60 mm


Summary

EMI-DLD-Shock Test

Powerful test-method that covers interesting

high-g-load and long duration pulse regime

Reproducible lab-test at moderate costs

Application of DLD-Shock Test: behavior of capacitors during high-g-load

Measurement of long duration shock pulses with autonomous data recorder

g-rec: versatile and robust measurement-tool

Medium caliber concrete penetration at high velocities

the smaller the ammunition, the bigger the acceleration


Thank you for your Attention!

Questions?

This work was funded by the

Federal Office for Defence Technology and Procurement BWB

(Bundesamt für Wehrtechnik und Beschaffung)

Further Information:

Dr. Manfred Salk

Fraunhofer EMI

Am Klingelberg 1

79588 Efringen-Kirchen / Germany

Tel.: +49 7628 / 9050 – 639

E-mail: [email protected]

Dr. Siegfried Nau

Fraunhofer EMI

Am Klingelberg 1

79588 Efringen-Kirchen / Germany

Tel.: +49 7628 / 9050 – 685

E-mail: [email protected]

Documents

Fuzing„s Evolving Role in Smart Weapons€¦ · © Fraunhofer EMI 8 10.000 g 3.300 ms (exp) 20.000 g 1.250 ms (exp) 30.000 g 0.800 ms (exp) 40.000 g 0.520 ms (exp) 50.000 g 0.350