LMS Solutions Durability testing

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Chiel Verhoeven

LMS Solutions

Durability testing

Solutions seminar Spain

2

Durability testing

1

Welcome and introduction

3

Structural testing

4

Acoustic testing

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3copyright LMS International - 2011

Durability: more than just breaking things

Video fragment from BBC’s Top Gear Challenge: Euro “Egg“ CAP test

Buy a cheap car

Drive 30 Mph on MIRA proving ground Test comfort and durability using eggs They get charged for every piece of trim

they loose

Data analysis Simulation

LMS Durability engineering solutions

Understanding Operational loads

Target setting & Test Procedures Physical Product Optimisation & Validation Design Optimisation Virtual Product Validation Mobile data acquisition Laboratory shaker trials Final Product Test Extensive field testing

LMS

TecWare

Virtual.Lab

Scadas recorder

Test.Xpress

LMS

TecWare

Scadas

recorder

Test.Xpress

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LMS Durability engineering solutions

Where to use durability for?

•

Predict when your product fails

•

Learn how your customers use your product

•

Validate your product in a shorter time

Agenda

Durability testing

2

Durability data acquisition

1

Scadas hardware

3

Durability processing

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• Tuned for durability applications

• IP54 dust and water protected frame

• Tuned for advanced N&V applications

• Operable with the recorder functionality

N&V & Recorder

Lab, In-field & unattended

SCR platform

Durability

Lab, In-field & unattended

SCD platform

• Tuned for classical N&V applications

• Derivative for dedicated Vibration Control frames

N&V

Lab & In-field

SCM platform

LMS SCADAS Mobile Technology

Product portfolio

LMS SCADAS Mobile Technology

Overview LMS systems

Scadas Mobile platform

Internal battery

No moving components

Autonomous measuring

CAN, GPS

Master-slave

SCR05 SCR01 SCR02 SCR09 SCR07

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LMS SCADAS Mobile platform

Overall functionality

4 to 72 channels

Master slave configuration for distributed systems and channel

expansion

Up to 204.8 kHz sampling rate per channel

24-bit DSP technology

150dB spurious free dynamic range

SCM05

SCM01 SCM09

SCM02

LMS SCADAS Mobile platform

Dimensions • W=345 • H=74 • D=300 Dimensions • W=203 • H=55 • D=278 Flexibility • wide range DC • wide range AC • battery with fuel gage • >100 minutes autonomy

Ruggedness

• Robust

• Advanced heat management • no fan

• -10 to 55o_{C ambient}

High performance

• 14MSamples/second • secured connection • long cable length

Connectivity

• 4-72 channels and beyond • master/slave

• V / ICP / MIC / Charge / Temperatures • strain gauges

• digital audio • GPS • CAN

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LMS SCADAS Recorder Platform

Based on LMS SCADAS Mobile platform

Autonomous recording on CompactFlash card

On-the-spot validation of measured data

Wireless PDA smart control with Bluetooth communication

On-board GPS and CAN

Parallel data streaming to internal memory & PC

Easy-to-use recorder software for acquisition measurement

set-up, instant data validation and data export

SCR05 SCR09

SCR01

SCR02

SCR07

LMS SCADAS Durability Recorder Platform

Incrementing on LMS SCADAS Recorder platform

Top performer in tough conditions

Water & dust protected – Ingress protection code IP54

Shock & Vibration protection - MIL-STD 810F

Strain, vibration and displacement measurements in one

single measurement card

SCD07 (IP54) SCD09

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LMS Scadas mobile modules

Accommodating a wide variety of NVH transducers

V8E: Voltage and ICP

VD8E: Voltage, ICP, differential inputs

VM8E: Voltage, ICP and microphone

VS8E: Voltage, ICP and digital audio

VC8E: Voltage, ICP and charge

VB8E: Voltage, ICP and bridge

DB8: Voltage and bridge

T8: Thermocouple

RV4: Torsional vibration inputs • Accelerometers: piezoelectric, ICP or capacitive • Force and pressure sensors: piezoelectric or strain gauges • Microphones and SI probes: conventional or ICP

• Strain gauges: conventional 120Ω/350Ωor semiconductor • Tacho sensors: inductive, capacitive, CAN or optical • Temperature sensors: type E, J, K, N, R, S and T thermocouple

Solutions seminar Spain

2

1

Scadas hardware

3

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LMS

TecWare

Virtual.Lab

Scadas recorder

Test.Xpress

LMS

TecWare

Scadas

recorder

Test.Xpress

Force

Moment

Stress/Strain

Displacement

Acceleration

Pressure

Temperature

Others

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Force

Moment

Stress/Strain

Displacement

Acceleration

Pressure

Temperature

Others

• Wheel forces • Component forces • Tension • Compression • Torque • Local stresses • Absolute displ. • Relative displ. e.g. damper, bushings • Engine torque

• Drive shafts

• Engine • Gearbox

• Brake pressure • Air pressure - dampers • Body accelerations

• Subsystems

• GPS – Global position • CAN signals

control unit quantities • Angle sensors etc. … WFTs

WFTs, Strain Gages, Torque Sensors

Strain gages DC-accelerometers Pressure sensors

Thermocouple Laser Laser, String pods

Which sensors to use ?

LMS SCADAS Modules

DB8

Eight channel Voltage / Bridge module (DB8)

Cost-effectiveuniversal module for durability data acquisition

Fully equipped bridge amplifier, sensor supply options and standard voltage input

Connectivity

DC accelerometers (MEMS, piezo-resistive),

Strain gauges,

Force and pressure transducers Potentiometers

Specifications

High quality 7-pin LEMO connectors Input mode selectable per channel 1/1, ½ and ¼ bridge configuration Bridge supply up to 10VDC Bridge balancing

120Ωand 350Ωbridge completion Internal shunt calibration

Support of differential and single-ended active sensors

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LMS SCADAS Modules

VB8-E

Eight channel voltage/ICP®/Bridge module

Most versatileScadas module standard voltage/ICP®/TEDS and fully

equipped bridge amplifier

sensor supply options and standard voltage input

Connectivity

ICP® accelerometers ICP® microphones

DC accelerometers (MEMS, piezo-resistive),

Strain gauges,

Force and pressure transducers Potentiometers

Specifications

Sampling up to 204.8 kHz High quality 7-pin LEMO connectors Input mode selectable per channel 1/1, ½ and ¼ bridge configuration Bridge supply up to 10VDC

Accurate bridge balancing through current injection

120Ωand 350Ωbridge completion Internal shunt calibration

Differential and single-ended active sensors

Maximum measurement power in one single box

Analog channels

DC Accelerometers (bridge-type capacitive,

piezo-resistive, MEMS-based) Strain gauges

(full-bridge, half-(full-bridge, quarter-bridge)

Load cells, pressure transducer Potentiometers

Signal conditioning of every channel is software selectable

Temperature

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Maximum measurement power in one single box

Built-in GPS and embedded CAN

external CAN Low-speed and

High-speed vehicle bus data Built-in GPSreceiver

Instant and accurate absolute time, position, speed

Speed

RPM

Simplify your set-up, reduce cabling errors and guaranteed high-quality data

Movie Quad

Instrumentation

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Software demo

LMS Test.Xpress

Movie Quad

Measurement

Link

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Measurement results

Example road surfaces

Solutions seminar Spain

2

1

Scadas hardware

3

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LMS Durability engineering solutions

LMS

TecWare

Virtual.Lab

Scadas recorder

Test.Xpress

LMS

TecWare

Scadas

recorder

Test.Xpress

How to understand fatigue content of loads ?

Comparison of 2 measurements

Most

damaging?

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What to do with the acquired data?

• Calculate damage - predict fatigue life

• Use data for simulation input

• Replay measurement on a laboratory shaker

Which parameters influence fatigue ?

Loads

Load level

Constant amplitude / variable amplitude

Uni-axial / multi-axial

Geometry

Load configuration

Notch severity

Local stress state

Material

Basic properties

Surface finish / manufacturing

Residual stresses

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Damage

Fatigue life (=1/Damage)

Damage

accumulation

Variable loadings

Rainflow counting

→

Cycles

SN-curve for

CA loading

Material

Loads

(Stress)

Geometry

Stress-concentration K

f

Identification of

Rainflow cycles

as basic

damaging events

:

Endo (1965). Rainflow counting for variable loads

from

load

level

to load level

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10

classification

into bins

load history

Rainflow-Matrix

:

the number of cycles

is cumulated in

the from-to cells

10 9 8 7 6 5 4 3 2 1

t

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Damage

accumulation

Variable loadings

Rainflow counting

→

Cycles

SN-curve for

CA loading

Material

Loads

(Stress)

Geometry

f

What is an S-N-curve ?

Low cycle fatigue High cycle f. Infinite life

Se S_ut

endurance limit

Number of stress cycles N [-]

F a ti g u e s tr e n g th [N /m m ²]

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How to understand fatigue content of loads ?

Palmgren (1924)-Miner (1945). Damage accumulation rule

Assume that, during the service life, we

have 500 loadings of type

1

(defined by

mid-value and magnitude),

1000 loadings

of type

2

and

10000 loadings of type 3,

the

Palmgren – Miner

rule states that

failure

occurs when

where

n

i

is the number of applied load

cycles of type

i

, and

N

i

is the pertinent

fatigue life

Damage

accumulation

Variable loadings

Rainflow counting

→

Cycles

SN-curve for

CA loading

Material

Loads

(Stress)

Geometry

f

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How to use the measured load data?

Damage

accumulation

CAE correlation

Fatigue life prediction

Accelerated

testing

Damage

accumulation

CAE correlation

Accelerated

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failure:

loading > strength

Applied loading vs. structural strength

applied loading

structural strength

(material + geometry)

probability

density

strength criterion

wider = safer, but more expensive

more scatter

less

scatter

Damage

accumulation

CAE correlation

Accelerated

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How can you accelerate a test ?

Increase the testing speed - ‘compress’ the time series

Increase the amplitude – less repetitions needed for the same amount of damage

Omit non-damaging events

Simplify the test – from variable loading to constant loading

Worst-case scenario testing – envelope of different user requirements

Basic principle = conservation of damage

Application case

Driving 1.2 million kilometers in 8 weeks

Accelerated durability testing cycles

Meeting 1.2 million km durability

requirement

Real tests would take 3 years

Large-scale customer data collection

5000 km Turkish public road data

Ford Lommel proving ground

Development of accelerated rig test

Target setting

Test schedule definition

Resulting test schedule 8 weeks

Test acceleration of factor

100

LMS engineers performed dedicated data collection, applied extensive load

data processing techniques and developed a 6- to 8-week test track sequence

and 4-week accelerated rig test scenario that matched the fatigue damage

generated by 1.2 million km of road driving.

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Real-life measurement setups

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