Vehicle Lightweighting: Materials, Processes and Life Cycle Assessment

Transcription

1 Vehicle Lightweighting: Materials, Processes and Life Cycle Assessment LCVTP Final Dissemination Event 21 st February 2012 Geraint Williams, WMG Workstream Partners: Ricardo, WMG, MIRA, Coventry University, TMETC, Jaguar Land Rover Associate Partner: Alpha Adhesives

2 LCVTP: Work Stream 7 Objective: > To develop materials and process technologies that will facilitate the introduction of lightweight solutions into future electric / hybrid vehicle programmes without compromising the overall life cycle impact.

3 Challenges and Considerations Product application > Structural performance and generation of CAE models > Durability Manufacturing implications > Formability and joining > Volume manufacture and introduction into existing facilities Environmental impact > Impact of alternative material on Life Cycle CO 2 > LCA methodologies

4 WS 7 - Key Tasks and Deliverables BIW Material Technologies Determine suitability of candidate materials and process combinations to minimise the weight of structural automotive applications. Provide robust design and process guidelines for the best assembly and joining methods for a given set of material / joint interfaces. Lightweight seat construction Identify and evaluate materials and process options for lightweight seat structure concepts. Lightweight EV architecture Understand the complexities and develop a scalable architecture model that can be applied to EV, REEV and Series Hybrid vehicles. Lightweight glazing Identify a lightweight glazing solution for each vehicle application that optimises the optical, acoustic and thermal transmission performance. Life Cycle Analysis Ensure that materials and process technologies identified are evaluated for their environmental performance to minimise any adverse impact. Deliverables Reports on current and emerging technologies Generic part and design data Validated concepts Design and application proposals Design and process guidelines Roadmap to future opportunities LCA indicator

5 Key Achievements Test methodology for composites developed and correlation with computer simulations established Viable medium/high volume composites manufacturing process for structural applications demonstrated BIW structural component weight saving of at least 20% Projected front seat weight saving of over 33% Lightweight glazing technology opportunity identified Rapid life cycle calculator developed and life cycle CO 2 footprint of LCVTP vehicle established Dissemination events included technology reviews (3), workshop training and demonstrations, internal and external publications and presentations

6 Some specifics Mechanical characterisation Process development Component application Environmental evaluation

7 Mechanical characterisation Purpose: To establish the structural capability of selected lightweight materials/process technologies against existing benchmarks Selection Multiple materials - supplier engagement activities Standardised testing (tensile, flexure, lap shear) Demonstration Candidate materials versus benchmark materials Testing demonstrator parts (flex, crush, fatigue, impact) Simulation FE model input and benchmarking Develop predictive FE model CR Technology validation Benchmark performance against predictive models

8 Demonstrator beam FEA correlation LS-DYNA, using developed MAT058 card, static flex > Indicates that modifications are required to model in key areas

9 Crush comparison video

10 Process development Rapid stamp forming Process developed for top-hat demonstrator Material heated to target temperature (230 C, continuous heating process) geometry and seat back part > Tool design analogous to sheet metal forming process > Med-high volume approach Transferred to heated mould tool (hand or shuttle, 10s, 100 C) Can use existing sheet metal stamping infra-structure Minimised cycle times (<90s) Mould tool closes and stamp-forms part (<10s) Achieve 50k+ PPA on a single line Part cools to de-mould temperature (60s, ~120 C)

11 Process development - Joining technology Principal aims: > Evaluate the state-of-the-art for joining processes > Investigate appropriate (production-relevant) joining methods for the candidate materials selected in WS7 > Provide timely input for demonstrator (top-hat/seat) testing

12 Adhesive bonding curing and surface optimisation Study with Alpha Adhesives to optimise cure properties of epoxy adhesive: > Heat curing (e.g. BIW paint bake) > Only just achieving cure with standard adhesive > Alpha re-formulated 1K adhesive for lower cure temp/time Improve bond strength +100% by optimising composite substrate surface finish > Peel fabric used in blank production > Joint efficiency is doubled

13 Component application - Lightweight seating Develop, manufacture and test an alternative lightweight seat back structure > Candidate material is PA6-GF60, as for demonstrator beam > Selected candidate process is a modified press-forming approach > Final design includes first stage optimisation steps Overall target is 40% lighter than Best in Class > Benchmark frame is 2.9 kg

14 X-Acceleration (g) Light Weight Seating: Correlation example 70 Acceleration - FEA Time (s)

15 Light Weight Seating: Thermoplastic Opportunity Steel Assembly Thermoplastic Concept CF Thermoset 17kg 12kg 11kg >200k p.a. 70k p.a. 500 p.a.

16 WS7 - LCA Approaches Process optimisation (SPMJ) > Develop a lean but robust approach to environmental impact assessment at product concept stage that is consistent with LCA and carbon foot printing methodologies > Validate proposals and roll out to project partners and other key stakeholders Strategic direction (Ricardo): > Develop top down methodologies for estimating the life cycle CO 2 emissions associated with different powertrain architectures > Demonstrate a lean methodology to provide strategic direction to industry for reducing environmental impact of complete vehicle or systems Demonstrator component assessment (WMG): seat, top hat