OMIS 661 Presentation – Intelligent System Case

Caterpillar uses optimization to reduce structural mass while improving structural strength

Presenters – Celeste Latham and John Kearsing

OMIS 661 Presentation – Intelligent System Case Agenda

•Concept Introduction •Structural optimization • Terminology • Optimization process • Caterpillar’s Virtual Product Development position • Optistruct demo • CAT optimization

Agenda

OMIS 661 Presentation – Intelligent System Case

Concept Introduction

Structural optimization is an automated technique that derives the optimal design of a structure given design criteria.

Structural optimization has the potential to:.

–Significantly reduce material costs by optimizing structural designs with respect to specified goals –Accelerate product development through the elimination of manual design and analysis iterations –Improve product quality and reliability by promoting early and frequent analysis of structural strength and life

OMIS 661 Presentation – Intelligent System Case

Concept Introduction

Material optimization Terminology

Topology optimization Optimal material layout in a given package space Shape optimization Optimal Shape of a given geometric feature Size optimization Parametric optimization Ex. Gage thickness, Beam sections etc

OMIS 661 Presentation – Intelligent System Case

Concept Introduction

Structural Optimization Process

Topology Optimization Size & Shape Optimization engineer engineer engineer Different Iterations Intelligent System Design Interpretation Final Design Intelligent System

OMIS 661 Presentation – Intelligent System Case

CAT & VPD

A Fortune 100 company, Caterpillar is the world's leading manufacturer of construction and mining equipment, diesel and natural gas engines and industrial gas turbines. The company is a technology leader in construction, transportation, mining, forestry, energy, logistics, electronics, financing and electric power generation. Key company facts : • ~$23,000,000,000 company • • • ~69,000 employees Averages 500 patents per year Over 1000 PhDs/CEO PhD

OMIS 661 Presentation – Intelligent System Case

CAT & VPD

• Every component on a CAT tractor is modeled in a 3D modeling system prior to creation – Millions of models. This has set the stage for Caterpillar’s Virtual Product Development Strategy.

OMIS 661 Presentation – Intelligent System Case

CAT & VPD

VIRTUAL PRODUCT DEVELOPMENT

• More time spent in the early stages of virtual product development to better reduce time spent maintaining the product in the later stages.

OMIS 661 Presentation – Intelligent System Case

VIRTUAL PRODUCT DEVELOPMENT

CAT & VPD

Product definition

Concept Detailed Design Testing

OMIS 661 Presentation – Intelligent System Case

CAT & VPD

VIRTUAL PRODUCT DEVELOPMENT

• • Structural Optimization is one focus of VPD Caterpillar is using Optistruct, a product developed by Altair Engineering, to help achieve the goals of VPD

Optistruct Demo

Topology Optimization

Radiator Bracket – Design Package Space ▲ Original bracket failed ▲ Reduce stress in bracket Courtesy TECOSIM GmbH, Ruesselsheim

Topology Optimization

Radiator Bracket – Optimization Results Courtesy TECOSIM GmbH, Ruesselsheim

Topology Optimization

Radiator Bracket – Geometry Extraction/Design Interpretation

VOLUME = 0.3

Density Threshold = 0.6

Courtesy TECOSIM GmbH, Ruesselsheim

Topology Optimization

Radiator Bracket – CAD Detailing of Concept Design Courtesy TECOSIM GmbH, Ruesselsheim

Topology Optimization

Radiator Bracket – Final Detailed Design

Design from Optistruct Final Interpreted Design

Courtesy TECOSIM GmbH, Ruesselsheim

Topology Optimization

Radiator Bracket – Design Validation Original Design

Max. v. Mises Stress Max. Displ. Mass

Optimized Design Courtesy TECOSIM GmbH, Ruesselsheim

Optimization of SUV Chassis Frame

Optimization Objectives: Re-design the Chassis Frame Minimize the Mass Maintain the same structural stiffness

Optimization of SUV Chassis Frame

Topology Optimization Identify the maximum design space

Optimization of SUV Chassis Frame

Topology Optimization Result Optimal Placement of Material

Optimization of SUV Chassis Frame

Evaluation of topology optimization result First Concept Design

Optimization of SUV Chassis Frame

Analysis of First Concept Design 300 250 200 150 100 50 0

Optimization of SUV Chassis Frame

Topology Optimization of First Concept Design Open C-Section Cross-member Topology optimization on shell structure: Re-define Material Placement Closed C-Section

Optimization of SUV Chassis Frame

Second Concept Design Open C-Section Closed C-Section Cross-member 300 250 200 150 100 50 0

-12%

Lighter Structure

Optimization of SUV Chassis Frame

Optimal Design 300 250 200 150 100 50 0

-23%

Design tuning using shape and size optimization

Optimization of SUV Chassis Frame

Designs Comparison Baseline Frame: Ladder Frame Design – 226 kg Optimized Frame: Lightweight Concept – 174 kg (-23%)

Topology Driven Vehicle Concepts

● Lightweight SUV Frame Concept – Baseline frame used for stiffness and modal targets ● ● Including Torsion Bar & Trans C/M Mass: 498(lbs) [226(kg)] **

** Includes mass of welds (3kgs)

● Performance Targets: – – – – – Twist: Vertical Bend: Lateral Bend: Bending Stiffness: Torsion Stiffness:

Target Weight Reduction 125lbs (25%)

18.7 Hz 27.1 Hz 29.0 Hz 3278 N/mm 121 kNm/rad

Topology Driven Vehicle Concepts

 Define all available package space, Loading, and BC’s  Topology Optimization for gross concept features  Interpret into first concept design  Topology optimization for concept refinement 

Interpret concept for final optimization and design details

Concept Development Process

Final Concept

Topology Driven Vehicle Concepts

● Final Concept Design – – – Primary Hydroformed Sections Mid Rail “C” Section Welded Body Mount Brackets – – – – 23% lower mass 25% fewer parts 50% less weld length Cost penalty: • $0.25 cost per lb saved ● Performance Results: – – – – – Twist: Vertical Bend: Lateral Bend: Bending Stiffness: Torsion Stiffness: 25.0 Hz (+34%) 27.8 Hz (+2.5%) 26.4 Hz (-9%) 3278 N/mm (0%) 159 kNm/rad (+31%)

OMIS 661 Presentation – Intelligent System Case

CAT Optimization

D8 Trunnion optimization

OMIS 661 Presentation – Intelligent System Case

CAT Optimization

Original Fabricated Trunnion Design – 2 pieces

Fabricated Version: Mass=

44.1 Kg

OMIS 661 Presentation – Intelligent System Case

Design Objective

Minimized Weight

Design Constraints

Von Mises Stress (Yellow Part) < 785 Mpa Max Principle Stress (Yellow Part) < 372 Mpa

Design Variables-Five

•Inside pocket •Neck Radius •Neck Transition •Bolt Plate Thickness •TRF Inserted Flange Thickness

CAT Optimization

OMIS 661 Presentation – Intelligent System Case

Final Design

CAT Optimization

Weight Results

weight 45 40 35 30 25 Current Optimized weight

CURRENT FABICATION DESIGN OPTIMIZED DESIGN Weight(kg) % Reduction

44.1

26.6

39.70%

OMIS 661 Presentation – Intelligent System Case Stress Results

Requirement: Max Principle Stress < 372 MPa Result: 187.9 MPa Requirement: Von Mises Stress < 785 Mpa Result: 757.3 MPa

CAT Optimization

Max. Load

OMIS 661 Presentation – Intelligent System Case Financial Results

CAT Optimization

• 40 % weight reduction from current production design • $136 cost savings per a part • 3260 parts are expected • $443,360 annual cost savings

OMIS 661 Presentation – Intelligent System Case Future Uses

•Expand the optimization process other product lines •Gain an estimated savings of $2 million in 2005

CAT Optimization

OMIS 661 Presentation – Intelligent System Case

CAT Optimization

Questions?