Transcript Environmental Shock Simulator

GHI’s ESSM
Environment Shock
Simulation Machine
A Powerful Concept
- Produces Equivalent Hard Surface Shocks For
Evaluation of Miniaturized or Hand-Held Devices
Copyright © 2005 GHI Systems, Inc.
All Rights Reserved
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Hard Surface Environmental
Shock Physics
Drops on hard surfaces produce the most severe
environmental shocks.



Have very high acceleration and frequency.
Results in very short stopping distances having high strain
rate.
Cause product case and internal damage
These dynamics can’t be accurately simulated by
programmed shock or drop test machines.

ESSM controls the variables of impact orientation, impact
surface and dynamics.
© 2005 GHI Systems, Inc.
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Parameters Needed for Simulation
Unrestrained non-tumbling free fall from threat
height
Impact surface to simulate environment
Controlled impact and sensor orientation
Drop velocity verification
Captured shock waveform for analysis
 Shock Response Spectrum
© 2005 GHI Systems, Inc.
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ESSM Vs Drop Shock Machine
DROP SHOCK
ESSM
Simulates Environment Shock
Exact drop height
Gauges impact velocity
Simulates the impact surface
Worst Case stopping distance
Repeatable dynamics
Easy for HS video to “see” the
impact dynamics
Small Lab space footprint
Easily relocated
Lower overall cost
Impact limited by MEP
Only equivalent drop height
Impact velocity not controlled
No impact surface - is fixtured
Stopping distance is limited
Dynamics limited by fixture
Difficult for HS video
Shows little of real
environment shock
Large relative footprint
Hard to relocate
Higher overall cost
© 2005 GHI Systems, Inc.
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Basic ESSM Elements
Drop height
Setting and
UUT release
Pre-Impact Triggered Retracting
Holders
Shock Sensor
On UUT
Guide Rods
UUT Grasper
Detachable
Impact Anvil
UUT Grasper
ESSM Seismic
Mass
UUT Guide
Stop Cushions
& Release
Triggers
72” Drop Height Scale &
Velocimeter Sensor
Surface
Simulator
Anvil
© 2005 GHI Systems, Inc.
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Basic ESSM
Base . . . . . . . . . . . 18”x16”
Seismic mass . . . . .120 lbs plus anvil
Shafts . . . . . . . . . . .SS 1.00” on 8” centers
Bearings . . . . . . . . .Recirculating Ball
Impact Anvil Size. . .8” w x 6” d
Anvil Material . . . . . SS or Hard Wood Block
Max Drop Ht . . . . . .72”
Max Impact Vel . . . 235.8 “/sec
Max UUT Wt . . . . . 5lb
Max UUT Size . . . . 6” Between Gripping faces*
Min UUT Size . . . . 0”
Overall Height . . . . 75” Standard, other heights
optional
* UUT may be gripped in various orientations.
© 2005 GHI Systems, Inc.
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ESSM Operation
Environment surface sample is installed on base anvil if required
UUT is mounted on carriage in desired orientation
Accelerometer is applied to UUT with main cable anchored to UUT
carriage and linked with thin flexible non-encumbering cable
UUT carriage is raised to desired height to match simulation
UUT carriage is released resulting in free fall toward anvil
Restrained UUT maintains orientation till impact
UUT Grippers are triggered to release prior to impact, Adjustable
UUT impacts anvil free of tumbling at desired orientation and
velocity
Shock data and pre-impact velocity are captured by GHI
instrumentation to correlated with environment shock damage
© 2005 GHI Systems, Inc.
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Feature FAQs
UUT Grippers (2) . . . . . . . . . . .2” Dia. Circular*
UUT Gripper Material . . . . . . . .Non conductive low
density plastic
Replaceable Grippers? . . . . . . Yes
Replaceable Anvil? . . . . . . . . . Yes*
Instrumentation, . . . . . . . . . . . .Shock Analysis
w/SRS optional
Impact Velocity . . . . . . . . . . . . .VS Standard
Price, Delivery . . . . . . . . . . . . .Contact GHI
* Other configurations Optional
© 2005 GHI Systems, Inc.
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Typical Design of Drop Release
UUT carriage release is set to desired
drop height and clamps tightened.
UUT carriage is raised to desired
height for drop and latched to UUT
carriage release hook on
electromagnetic solenoid.
This allows seamless height setting for
desired EUE simulation.
Actual velocity is monitored by GHI
velocimeter.
© 2005 GHI Systems, Inc.
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UUT Gripper Design Overview
Orientation Rotation Lock
Quick-adjust
Gripper Fingers
© 2005 GHI Systems, Inc.
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Minimum 2” Gripper Release
Height
Simulated product is 5” wide x 2.5“ thick x 2.5” deep,
shown in free fall at 2” above impact surface.
© 2005 GHI Systems, Inc.
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2.5” Format Hard Disk Drive in
Grippers
Shown before release. Angle set to
15o impact angle.
© 2005 GHI Systems, Inc.
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Grasping Flexibility
2.5 Inch format hard disk drive shown grasped in the Z axis for a
precise X-Y plane corner impact shock.
© 2005 GHI Systems, Inc.
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Grasping Flexibility
Cell phone held for random position
shock - object can be released an
inch or two above impact surface.
Free fall can be set up to 72 inches
above the impact surface.
Impact surface can be changed to
comply with particular test protocols
or to simulate actual environmental
threats.
Pre-impact velocity will be
measured as well as shock
acceleration time history. SRS
software for pyro type analysis is
optional.
© 2005 GHI Systems, Inc.
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Strain Gauge Use
Strain Gauges are compatible with the GHI
Systems Data recording and analysis system.
Film devices may require bridges and
amplification, solid state devices are simpler.
Dynamic strain induced failures may be
measured.
© 2005 GHI Systems, Inc.
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Grasper Release Action
Release Spring
Latch Bar
Released Condition
Latched Condition
© 2005 GHI Systems, Inc.
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HS Video Frame - Corner
© 2005 GHI Systems, Inc.
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ESSM Summary
ESSM simulates environmental drop height, impact velocity, and
impact surface.
Impact surfaces quickly replaceable for specific test protocols.
Maintains Product Orientation to simulate actual events.
Flexible UUT holding orientation options.
High sample rate data system for impact velocity, uniaxial or triaxial
shock acceleration and dynamic force – up to 1 MHz.
Full Shock SRS S/W Module Optional.
Small footprint 18 “ x 16 “, easily relocated.
Sturdy machine base, 120 lbs, prevents machine rocking.
Safe low voltage (12V DC) control, no compressed air needed.
Open design makes high speed video easy.
© 2005 GHI Systems, Inc.
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Contact
GHI Systems, Inc
916 N. Western Ave. Suite 201
San Pedro, CA 90732
Phone: 1-800-444-7978
Web Site: www.ghisys.com
© 2005 GHI Systems, Inc.
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