test bench for activatable batteries · introduction fraunhofer emi as an engineer for customized...

© Fraunhofer EMI

60th Annual NDIA

Fuze Conference

May 2017

S. Hess, C. Glößner, S.

Nau, B. Lang, V. Trinler

TEST BENCH FOR ACTIVATABLE BATTERIES

Development of Customized Dynamic Test Systems

Introduction

Fraunhofer EMI as an engineer for customized dynamic test systems

exemplified by a test bench for activatable batteries

Project definition and requirement specification

Concept and technical approach

Realization and first measurements

Summary

AGENDA

3

Introduction

Methods for generating defined shock loads

Nau et al. „Generation and Measurement of Long Duration High-g Accelaration Profiles“,

55th Annual Fuze Conference, Salt Lake City, 2011

D. Hayles, DTRA, Fuze Conference 2010

acce

lera

tio

n [g

]time [ms]

measurement

50 kHz filtered

- Numerical simulation

- Experimental data

Example: 30.000 g, 800 µs

4

Introduction

Methods for generating defined shock loads

Nau et al. „Generation and Measurement of Long Duration High-g Accelaration Profiles“,

55th Annual Fuze Conference, Salt Lake City, 2011

D. Hayles, DTRA, Fuze Conference 2010

required velocity: v0 > 100 m/s

5

Introduction

Pressurized air gun

Working pressure: max. 30 bar, vessel volume: 10 l

Caliber: 45 mm, barrel length: 2 m

Muzzle velocity: up to 175 m/s with m = 130 g

control panel

Inner view to control cabinet

6

Introduction

High-velocity powder gun HVPG

Caliber: 60 mm (Smoothbore)

Barrel length: 6 m

v0,max: 2850 m/s (m = 180 g )

pmax: 650 MPa

Features: use of conventional

propellants

One of the fastest

powder guns in Europe!

2500

2510

2520

2530

2540

2550

2560

175 176 177 178 179 180 181

v16

[m/s

]

test number

v16 = 2527 m/s ± 17 m/s

1600

1800

2000

2200

2400

2600

2800

3000

0 5 10 15 20

ve

loc

ity v

(m

/s)

target distance x (m)

7

Developing dynamic test systems

Test bench for activatable batteries

Expertise in generation of defined acceleration profiles

Defined-Long-Duration (DLD) Shock Test

Expertise in design and construction of dynamic test systems

Several commercialized accelerator systems

Diehl & Eagle Picher needs a:

Flexible laboratory test bench

Various g-loads combined with

Various rotational speeds

Adaptable for different battery types

Withstand thousands of tests per year

© Diehl & Eagle Picher

8

Developing dynamic test systems

Test bench for activatable batteries

Activatable fuze batteries, a short introduction:

Used in fuzes for artillery, mortar and naval gun

ammunition

Long shelf-life

Separation of electrolyte and cell stack during

storage

During gun launch the electrolyte is released by

an activation mechanism and wetted the cell stack

The activation mechanism is driven by the

acceleration

Wetting is mainly driven by the angular velocity

© Diehl & Eagle Picher

© Diehl & Eagle Picher

activatable

fuze battery

9

Test bench for activatable batteries

From requirement specification to realization

Electrical connection during activation

Voltage and current measurement

External electric load

Compliance to European law (CE conformity)

Physical conditions for battery activation:

Linear acceleration for activation:

Amplitude: 1’000 g to 10’000 g

Duration: 0.4 ms to 2 ms(real ammunition, e.g. PzH2000: 12’000 g)

Simultaneously:

variable rotation speed

from 0 rpm up to 18’000 rpm(buzz saw: 7’500 U/min) 0

2.000

4.000

6.000

8.000

10.000

0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8 2,0

required

Duration [ms]

Acce

lera

tio

n [

g]

© Diehl & Eagle Picher

10

Test bench for activatable batteries

From requirement specification to realization

Approach (developed in cooperation with D&EP):

Generation of g-load for activation by a defined deceleration during impact

Independent generation of rotation (1st) and axial acceleration (2nd)

Use of a rifled barrel is not possible

Keep axial g-load from the ball bearing by a momentum trap

Transmission of the electric signals during the activation process (4-wire)

Battery

initial, soft

acceleration

<< g-load

Moment-

um trap

defined g-load

(compression structure)

shock absorber

rotating barrel electric measurement

11

Test bench for activatable batteries

Experimental and numerical analysis of damping elements

Experimental characterization of different damping elements

Compressive elements

Foams (metal and glass)

Honeycombs

Crashtubes

Damping pads (viscoelastic)

Profile dampers

Numerical design and characterization of damping elements – if appropriate

material model is available

12

Numerical design and characterization of damping elements

13

61 62 63 64 65 66

-500

0

500

1000

1500

2000

Beschle

unig

ung [g]

Zeit [ms]

Messung

Simulation

Characterization of damping elements

g-rec and test-projectile

Measurement

Simulation

Time [ms]

Accele

ration

[g]

14

High-speed slip ring for signal

and power transmission

Test bench for activatable batteriesGalvanic connection between battery and electric load

Sabot with battery

with sliding contacts

insolation tube with

inserted sliding contact

© D

iehl &

Eagle

Pic

her

15

Test bench for activatable batteries

16

Test bench for activatable batteriesRealization and first tests

Rotational speed: 6.000 U/min

Frame rate: 10.000 fps

17

Test bench for activatable batteriesRealization and first tests

1 2 3 4 5 6 7 8 9

-200

0

200

400

600

800

1000

1200

Be

sch

leu

nig

un

g [g

]Zeit [ms]

g-load for activation(recorded with g-rec at same test setup)

Battery voltage vs. time• external measurement with variable load

steps in voltage plot

Time [s]Time [ms]

Vo

lta

ge

[V

]

Acce

lera

tion

[g]

Voltage raw data

18

SummaryDeveloping test benches for defense technology application

Fraunhofer EMIs expertise in:

Generating defined acceleration profiles

Construction of dynamic test benches

Tailor made test bench for activatable batteries

Basic concepts of the test bench

Numeric simulations

First test results

If you need a customized test bench

for your lab, feel free to contact us.

Further Information:Further Information:

Sebastian Hess

Fraunhofer EMI

Am Klingelberg 1

79588 Efringen-Kirchen / Germany

Tel.: +49 76 28 / 90 50 – 631

E-Mail: sebastian.hess@emi.fraunhofer.de

Thanks for your Attention!

Questions?

Dr. Siegfried Nau

Fraunhofer EMI

Am Klingelberg 1

79588 Efringen-Kirchen / Germany

Tel.: +49 76 28 / 90 50 – 685

E-Mail: siegfried.nau@emi.fraunhofer.de

This work is funded by DIEHL & EAGLE PICHER GmbH