07 - douglas smith - making jeep 2011 grand cherokee

7/30/2019 07 - Douglas Smith - Making Jeep 2011 Grand Cherokee

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Great Designs in Steel

2011 Grand Cherokee

Doug Smith

May 18, 2011


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Body Structure Outline

Body Functional Objectives: Essence of the Grand CherokeeMandates:

Improve performance, increase size & lower weight

Body Stiffness/Torsion/Bending

Durability

NVH

Impact Performance:

3rd Party Rating including Top Safety Pick (4x SWR Roof Crush)

Trail Rated Performance

Body Design Body Topology Evaluation

Section / Connection / Continuity

Structural Front End Module (FEM)

Steel Gage and Grade Selection

Resultant Components Chart

Development Welding Structural Adhesive

Multi - Disciplinary Optimization (MDO)

Structural Efficiency Calculation

Structural Adhesive Application

Body Static Stiffness

Body Modes

NVH


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Body Structure Outline

Development - Continued Tow Hooks

Water Fording

Performance Confirmation Road Test Simulator (RTS) Validation

Proving Grounds Duty Cycles

Impact Performance: 3rd Party Rating including Top Safety Pick (4x SWR Roof Crush)

Trail Rated and Rubicon Performance


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Body Functional Objectives:

Durability & Capability Driver Confidence Global Body Functional Objectives: Essence of the Grand Cherokee

Mandates:

Body Stiffness/Torsion/Bending

Durability

Impact Performance:



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WK Load Cases & Functional Requirements

Roof Crush

Platen angle

4 X GVW

Side Impact

FMVSS 214

IIHS Side impact

Euro NCAP

Front Impact FMVSS 301

40% offset direct push on Rail

Full Flat Frontal

Euro NCAP

Front & Rear Durability & Fatigue Loads

(with and without max payload)

Vertical 3G load at Susp mount(In phase & Out of phase)

Cornering Load2G Lateral load

Rear Impact FMVSS 301

70% offset direct push on Rail

Liftgate LoadingProp Rod Loads

Hinge loading

1st & 2nd Row Seat FMVSS 207 / 210 Belt

Torsional/Bending Stiffness

Sill loads Wheel Input


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Body Design:

Experienced Engineers / State-of-the-Art Tools

Body Design Body Topology Evaluation

Section / Connection / Continuity

Structural Front End Module (FEM)

Steel Grade Selection

Resultant Components Chart


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Topology:

Mass and Geometry Optimized to ObjectivesTypical Topology Process

Packaging Volume

Holistic Forces:

Safety

Refinement

Durability

Topology Results

Spatial load image

Beam Model

Load paths

Body Design

Detailed Components

Optimization

Steel Gauge & Materials

Toe Board

Crossmember

Shock tower

Upper Load

Path

Component Topology Design Application


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Section / Connection / Continuity:

Energy Management Strategy and Execution


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Structural Front End Module:

Functional System and Plant Build Optimization

Hood Slam

Torsion

Tow Hook

Push / Pull

Tow Hook

Push / Pull

Lo Speed Impact No-Fire Threshold & 16 mph

Hi Speed Impact 20-40 mph

Front-to-Front Compatibility


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High Strength Steel Usage:

Weight Reduction and Impact Performance

50% HighStrength

Steel

47%

42%

4%4% 3%

2011 Grand Cherokee MaterialUsage

Mild Steel

HS Steel

AHS Steel

Hot Stamp

Other

High Strength Steel: YS > 200 MPa

Hi h S h S l U


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Previous Grand Cherokee

2011 Grand Cherokee

New Vehicles

29%

High Strength

50%High Strength

70%

High Strength

High Strength Steel:

YS > 200 MPa

High Strength Steel Usage:

Weight Reduction and Impact Performance

WK B d C t Ch t


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WK Body Components Chart:

Body Shop Build Strategy

B d D l t


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Body Development:

Body Complete -- Jeep

Development Welding

Structural Adhesive

Multi - Disciplinary Optimization (MDO)

Structural Efficiency Performance Factor (PF)


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WK U d b d S t W ldi


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3308 Spot Welds in Underbody Shell

WK Underbody Spot Welding:

Connecting the Structure for Jeep Capability

WK Upperbod Spot Welding


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2069 Spot Welds in Upperbody Shell

WK Upperbody Spot Welding:


WK MIG welding:


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112 Mig Welds in Body Shell (Total mig weld length of 3494mm)

WK MIG welding:


WK Welding Complete:


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5489 Total Welds in Body-in-White Complete

WK Welding Complete:


WK Body Adhesive & Anti Flutter:


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Structural Adhesive (3mm bead) 108.6m total length

Anti-Flutter (5mm bead or gum drop) 8.3m total length

WK Body Adhesive & Anti-Flutter:

Finalization of Body Build Construction

WK Multi Disciplinary Optimization (MDO):


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Gages maintained for critical impact and

durability parts

Total Weight Savings = 23 kg

No change in bending and torsion modes

No degradation in mobility responses

Maintained overall BIW NVH responses

COLOR KEY

Downgaged

Upgaged

No Gage Change

WK Multi - Disciplinary Optimization (MDO):

Wt. Optimization with no Functional Degradation

Resultant Body:


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Resultant Body:

To Be Classified as a Jeep

Development Body Static Stiffness

Body Modes

NVH

WK BIW Static Stiffness:


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WK BIW Static Stiffness:

Solid / Confident Driving Experience

Bending Stiffness = 10200 N/mm (CAE)Torsional Stiffness = 23000 N-m/deg (CAE)

Torsional Stiffness Setup Bending Stiffness Setup

11WK BIW Normal Modes:


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11WK BIW Normal Modes:

Solid / Confident Driving Experience

First Torsion Mode 43 Hz First Bending Mode 51 Hz

11WK Mobility Responses to Inputs @ Body


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11WK Mobility Responses to Inputs @ Body

Attachments to Cradles: NVH Achieved

Front Cradle Front Body Attachment Front Cradle Rear Body Attachment

Rear Cradle Front Body Attachment Rear Cradle Rear Body Attachment

TARGET TARGET

TARGET TARGET

Target Met: < 0.2 mm/sec/N

11WK Acoustic Responses to Input @ Body


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11WK Acoustic Responses to Input @ Body

Attachment to Cradles: Driver Delight

Front Cradle Front Body AttachmentTARGET TARGET

TARGET TARGET

Front Cradle Rear Body Attachment

Rear Cradle Front Body Attachment Rear Cradle Rear Body Attachment

Target Met: < 55 dB

Tow Hooks:


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Tow Hooks:

Rugged Performance and Capability

Development Tow Hook Development


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Tow Hooks:


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A Jeep Queue

Front Tow Hooks (Two per Vehicle RT and LT) / Rear Tow Hook (one per Vehicle LT)

1. Design for Impact Requirements

1. Requires pulse separation between low speed threshold vs. 16 FF.2. Common calibration with and without tow hooks.

2. Design for durability Requirements

1. 1.0 /1.5 GVW pull.

2. 2.0 GVW pull with no separation.

3. 0.9 GVW 90 deg outboard pull no separation.

4. 0.5 GVW push/pull (BUX).

Tow Hooks:

Complex and Punishing Requirements

Tow Hook Design:


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Tow Hook Design:Engineered Geometry for Multi-Purpose Objectives

Front Tow Hook Development:


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Front Tow Hook Development:

System Level Confirmation Testing


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Tow Hook Development - Rear

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Rear Tow Hook Development:


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Rear Tow Hook Development:

System Level Confirmation Testing

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Water Fording:


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Water Fording:

Trail Rated Requirement

Development Body Sealing - 20 Water Fording Define P/1/P2 Sealing


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Water Fording Requirements:


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20 inches water

fording line

Water Fording

69.4 meters of sealer on BIW

76.4 meters including closures and hem sealing

Water Fording Requirements:20 inches of Water Submersion Performance

Water Fording:


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Water Fording:Body Sealer Robust Joints

Water Fording:


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Robotically Applied Sealants - 76.4m total length

Water Fording:Body Sealer Robust Joints

WK Water Fording:


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WK Water Fording:Capable Results Achieved!

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Performance Confirmation:


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Performance Confirmation:Legendary Jeep Performance

Confirmation Road Test Simulator (RTS) Validation

Proving Grounds Duty Cycles

Impact Performance:


Trail Rated and Rubicon Performance

WK Road Test Simulator Testing:


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gAccelerated Discovery and Durability Results

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2011 WK on Road Test Simulator Rig

SUV Body/Chassis PG Durability Duty Cycle

Represents 95th Percentile Usage Customer 150K Customer Equivalent Miles

Testing Performed to 2x Life

WK Pro ing Gro nds Testing


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WK Proving Grounds Testing

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WK NCAP Results


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WK NCAP Results

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Driver

Passenger

Front MDB

Rear MDB

Front Pole

Overall Vehicle Rating

Mode

Rating

Rollover

2011 WK NEW US NCAP RATINGS

Frontal

New NCAP Mode

Side

WK IIHS Offset:


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All Injury Criteria in Green Zone

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0% 25% 50% 75% 100%125%150%175%200%225%

HIC

Nij - Tension-Extension

Nij - Tension-Flexion

Nij - Compression-Extension

Nij - Compression-Flexion

Neck axial compression

Neck axial tension

Chest acceleration (3ms clip)

Chest compression

Sternum deflection rate

Viscous criteria

Left knee displacement

Left upper tibia index

Left lower tibia index

Left tibia axial force

Left foot acceleration

Left femur force

Right knee displacement

Right upper tibia index

Right lower tibia index

Right tibia axial force

Right foot acceleration

Right femur force

Poor Marginal Ac ceptable Goo d Meas ured V alues

2011 Jeep Grand Cherokee

IIHS Side Impact:


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pAll Injury Criteria in Green Zone

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WK IIHS Side Crush:


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After-test Geometry in Green Zone

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Table From IIHS website:


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Model Overall ratingCurb weight(lb)

Peak force(lb)

Strength-to-weight ratio

Jeep Liberty

2008-10

models

Dodge Nitro

2007-10

models

4,245 21,073 4.96

Toyota

Highlander

2008-10

models

4,325 20,511 4.74

Toyota Venza

2009-10

models

4,037 18,977 4.70

Jeep Grand

Cherokee

2011 models

4,655 21,545 4.63

Dodge

Journey

2009-10

models

4,318 19,649 4.55

Good Acceptable Marginal Poor | Vehicles are listed in order of performance

Roof Crush Rating : Good

IIHS Classification: Roof Crush Rating Good

2011 Jeep Grand Cherokee:


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pTrail Rated Performance

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Questions & Answers


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Questions & Answers

Q & A

Making Of The 2011 Jeep Grand Cherokee


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Making Of The 2011 Jeep Grand Cherokee

Thank You for Your Attention!

07 - douglas smith - making jeep 2011 grand cherokee

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