Redesigning the Wheel A Multifaceted Approach to Enhanced Mining Wheel

and Tire Safety

WSN Mining Health & Safety Conference 2013

University of Windsor Mechanical, Automotive and Materials Engineering

Aleksander Tonkovich Weldon Li M.A.Sc. Candidate Ph.D. Candidate

Sante Di Cecco William Altenhof M.A.Sc. Candidate Academic Advisor

Presentation Outline • Introduction and Motivation

– Motivation behind the research

• Research Purpose and Objectives

– Multi-piece wheels and why they are needed

– Multi-piece wheel failure modes

• Current Research Endeavours and Goals

– Historical Wheel Tracking Database

– WingFil: A Tire Foam Filler

– Innovative Wheel Safety Shield

– Advanced Wheel Redesign

• Concluding Remarks and References

Research Motivation

• Safety is the name of the game – This is the main focus of our research.

• Tragically, failure of wheels tend to lead to fatalities, not just injuries

• Motivation based on incidents and associated reports from around the world.

[4]

#1 Goal is to make workplaces and heavy vehicles safer to operate and maintain

• What are multi-piece wheels used for?

• Tires of large sizes (up to 14 feet tall) and sidewall thicknesses (sometimes >8 inches) are necessary for heavy mining vehicles and other off-the-road (OTR) vehicles. – High Payload Requirements - to ensure high productivity meaning high

tire pressures (up to >150 psi) are required.

– Harsh Operating Conditions – requiring high cut and wear resistance is needed for OTR tires.

Introduction to Multi-Piece Wheels

Operating weight of > 650 tons; 400 ton payload

• Why are multi-piece wheels required?

– Unlike passenger and light truck vehicles where tire beads are simply pried over the wheel flange, OTR applications are much more difficult to mount

– Typically large OTR tires cannot be mounted to a one-piece wheel without damaging the tire or wheel flange due to large and stiff tire beads. Therefore, multi-piece wheels that assemble like a puzzle are necessary.

Introduction to Multi-Piece Wheels, cont’d

• Most common failure modes result in wheels and tires not performing as they are intended or designed to.

• This results in components not staying properly engaged due to:

– Tire explosions, fires, or other failures (eg. “Zipper” Rupture)

– Tire blowouts due to fatigue failure, wear, corrosion, damage, deformation, or improper assembly of wheel components [7]

• The danger of multi-piece wheel failures are not limited to the risk associated with the failure of the wheel as a supporting structure of the vehicle, but the explosive loss of pressure that is observed.

• Improving wheel safety is paramount to improving mine safety.

Failure Modes of Multi-Piece Wheels

Exploded mining vehicle tire

Crack

Current Research Endeavours and Goals • Educate ourselves on mining wheels and vehicles , and the

environment they are exposed to:

– Mine site, supplier, and vehicle repair facility tours

• Quantify aspects of multi-piece wheel loading

– Vehicle data acquisition at mine sites

• Educate the mining industry to increase knowledge of multi-piece wheel potential dangers

– Attend WSN Technical Advisory Committee meetings

– Present research at:

• Canadian Institute of Mining, Metallurgy, and Petroleum’s (CIM) Maintenance Engineering/Mining Operators’ (MEMO) Conference

• Health and Safety Ontario’s (HSO) Partners in Prevention Conference

Bucket was raised up and lowered down to excite the tire in order to get large, measurable deflections.

• Understand the failure modes and life cycle of wheels and tires – Extensive historical wheel failure database development

– Examine wheel handling regulations and improve where possible.

• Increase safety of multi-piece wheels and improve their design

Current Research Endeavours and Goals

– Use innovative engineering techniques to examine and improve wheel designs through the development of virtual tire and wheel models

– Safety shield design, model development, and prototype implementation

– Determine feasibility of foam filling tires and develop new materials and inflation processes

– Develop an innovative wheel concept that mitigates safety risks through improved design

• Finite Element Analysis (FEA) is a powerful tool implemented in the study of wheels and tires

• Tires pose great challenges in virtual modeling due to their complicated and complex structures

The Power of Finite Element Analysis

Virtual models are validated with real world data, and then allow for a

wide range of versatile virtual testing that may

otherwise be impractical or impossible

• The virtual tire/wheel model was built using finite element (FE) method for tire 29.5-29 used in R2900G underground loader.

• The FE model was validated in the following steps:

1. The model was built to meet the tire engineering data – static load vs. deflection, provided by tire manufacturer.

2. The tire was tested under static loading condition at mine site and simulations were conducted under identical conditions with the tests and the tire deflections were compared.

3. Quasi-static experiments were conducted and the measured wheel axle displacements were used in the FE model as driving forces and tire lateral and in-plane deflections (longitudinal - y and vertical - z direction) were compared.

Virtual Model Development and Validation

N – numerical data E – engineering data

Vertical displacement

80 mm

Lateral deflection 36.5 mm

Bucket raised up and pushes against the rear bumper of a CAT 990

Tire moves down

91 psi

23,400 kG

• Purpose To identify the most frequent damage to wheels that requires repair

Use as a tool to determine the average life of wheels – something that

has never been done previously.

Understanding what causes wheel damage and scrapping is the first step to preventing failure, increasing safety, and decreasing downtime.

• Accomplishments to Date An extensive new statistical wheel tracking database was created based

on scrap wheel info with an easy and simple to use interface

Organizes information based on available wheel information using numerous criteria of interest

It is recommended to actively track all currently in-use wheels to provide usage statistics faster and to enable heightened awareness of necessary maintenance prior to failure

Wheel Tracking Database

Safety Shield Design

Safety Shield Goals

• Fail-safe device that can be applied to currently in-use wheel designs

• Protects the wheel in two different ways: • Physical barrier between operators and maintenance personnel and the wheel should failure occur • Protects the wheel from impact and abrasion

• As simple and financially viable as possible

Safety Shield Design • Lowers risk levels by requiring zero pressure

during wheel removal

• The shield is considered a consumable resource

• Ultimately there to protect workers should wheel or tire failure occur.

• A finite element model of the shield has been developed and is being used for simulation purposes and design validation.

• Major industrial supporter, North Shore Industrial Wheel Mfg., will potentially build prototypes to test once a final design is determined

Simulations include:

• Harsh impact and abrasion simulations

• Tire blow out simulations

• Combining the shield with five-piece wheel assembly model and performing fatigue life analysis

Safety Shield Future Development

Foam Filled Tires

• A promising means to improve wheel safety and vehicle operation

- Potential Advantages: Elimination or reduction of air pressurization; reduced vehicle downtime

- Potential Challenges: Ride quality; heat build up; extra mass

• An initial investigation of tire foam filling was conducted to determine its mechanical performance, and to experimentally and numerically characterize the material properties

• WingFil was selected for the initial study based on its use in small tire foam filled applications

• Testing of the foam consisted of:

– Cyclic compressive testing

– Numerical material model development

– Initial simulation of a tire filled with WingFil under normal operation conditions

With a proper investigation of the foam materials and the filling process, it is believed the potential challenges can be overcome

WingFil Experimental Testing

• Material testing of WingFil tire foam filler has determined its stress-strain behaviour for 50% compaction

• Observations:

– Cyclic loading of the foam reveals hysteretic behaviour

• Likely caused by microvoids closing over time

• Appears to stabilize after the first 50 cycles

– The peak stress of the foam decreases marginally with cycles

• Attributable to foam damage over time

Wingfil Material Model Development

• A material model emulating WingFil foam has been developed using FEA large deformation code, LS-DYNA

• The model is based on a Simplified Rubber material model, which utilizes many of the rubber foam’s material properties as input

• The material model was validated against experimental test observations using three different criteria:

– Downwards Deformation: 1.83% Error

– Side-bulge Deformation: 8.97% Error

– Compaction force: 14.0% Error

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Foam Filled Tire Simulation

• After foam material model development and validation, the foam was simulated within a tire model previously validated by the research group

• The numerical foam filled tire was simulated under static loading conditions typical of vehicle operation

– Stiffness of the foam tire was extracted from the simulation and compared against that of a pneumatic tire

Tire Foam Filling Future Development

• Based on initial results from foam filled tire simulations, the following changes are being investigated: – Ensure foam remains in contact with tire sidewalls during

simulation

– Use inflated tire dimensions (recommendation based on supplier information)

• Experimental testing of a Wingfil filled tire is required to validate the current model – Possible with current industrial partners’ support

• Once the current foam filled tire model is validated, consider: – Investigating suitable replacement foams to improve ride quality

– Developing a hybrid partially pressurized/partially foam filled tire for mining operation

Innovative Wheel Design - Concepts

New design focuses on removing the lock ring since this is the key part to cause wheel failures due to wear, cracks and incorrect assembly. Threaded-connection

Rim base comparison between new design and conventional locking design

Thread connection for safety

After installation

Threads

Installation

Tire

Threaded-connection design

Lock ring design

Material added for the

proposed design

Innovative Wheel Design – Simulation Results Mechanical Performance of the Threaded-Connection Design

1. BS band pull-out tests - assess the engagement capability of rim components

Conclusion: Threaded-connection design is almost twice as strong as conventional design to maintain proper engagement of rim components.

2. Stress level assessments

Maximum Von Mises stress on rim base front region:

Conventional lock ring design: 136 MPa

Proposed threaded-connection design: 96 MPa

29% reduction

3. Fatigue life estimates

Steel_UML_200 (Sy = 146 Mpa, Sut = 200 Mpa) was used to assess fatigue life

Estimated minimum fatigue life on rim base front region:

Conventional lock ring design: 1.240×107

Proposed threaded-connection design: 2.896×107

fatigue life was doubled

P

P

W

Vertical displacement

(a) (b)

Thread connection Lock ring design

(a) (b)

• Using innovative engineering techniques to increase wheel safety

• The most significant benefit of our research to date is simply bringing to light the potential dangers of multi-piece wheels

• Building relationships with industrial partners has made our research group part of their incident review process and provides us with information on any wheel related incidents

Conclusions

Acknowledgements This research project would not be possible without the gracious support of the following associations and companies:

- The Workplace Safety and Insurance Board of Ontario

- Workplace Safety North

- North Shore Industrial Wheel Mfg.

- Goodyear Off-the-Road (OTR) Tire

- Goldcorp’s Musselwhite Mine

- Xstrata’s Nickel Rim and Copper Kidd Mines

- Royal Tire

- Fountain Tire

- McDowell-Driftech

- The Ontario Graduate Student Program

- The Natural Sciences and Engineering Research Council of Canada

References 1. CBC News Online. "CBC News Indepth: Workplace safety." CBC News. N.p., 29 Apr. 2006. Web.

22 Aug. 2011. <http://www.cbc.ca/news/background/workplace-safety/dyingforajob.html>.

2. Parsons, Lee. "Workplace deaths soar in Canada." World Socialist Web Site. International Committee of the Fourth International, 29 Dec. 2006. Web. 12 Oct. 2011. <http://www.wsws.org/articles/2006/dec2006/cana-d29.shtml>.

3. MASHA. "Traumatic Fatal Injuries 1998-2008." Mines and Aggregates Safety and Health Association. Workplace Safety North, 8 Oct. 2008. Web. 5 Nov. 2011. <http://www.masha.on.ca/statistics.aspx>.

4. MSHA. "MSHA - Preliminary Accident Reports, Fatalgrams, FatalInvestigation Reports and Metal/Nonmetal Monitor Home Page." Mine Safety and Health Administration. N.p., n.d. Web. 2 Oct. 2011. <http://www.msha.gov/fatals/fab.htm>.

5. Month. "Census of Fatal Occupational Injuries Summary, 2010 ." U.S. Bureau of Labor Statistics. U.S.D.O.L., 25 Aug. 2011. Web. 10 Oct. 2011. <http://www.bls.gov/news.release/cfoi.nr0.htm>.

6. “Positioning Canada for Continued Competitiveness in the Mining, Minerals and Metal Industry”, A Submission to the Competition Policy Review Panel from the Mining Association of Canada, January 2008

7. “Health and Safety Statistic Status Report 2010”, WorkPlaceSafetyNowth mining sector.

8. “Truck tire explosions claim two more lives”, Saskachewen Labor, Occupational health and safety, November 2004.

9. Banting, Richard. "Driving towards ZERO: Controlling key equipment hazards to eliminate incidents." Mobile Equipment Symposium. Workplace Safety North. Holiday Inn, Sudbury, ON. 30 Nov. 2010. Lecture.

References, cont’d

10. “Equipment Operator Killed by a Lock Ring Propelled from a Multi-piece Rim Wheel”, State of New York Department of Health, Fatality Assessment and Control Evaluation (FACE), Case Report: 07NY137.

11. “Laborer killed While Inflating a Tire Mounted on a Multi-piece Rim Wheel”, FACE, Massachusetts Case Report: 03-MA-057-01.

12. Tyre Fitters Workshop, 2004, Townsville, North Queensland, Australia.

http://www.dme.qld.gov.au/zone_files/inspectorate_pdf/tyre_fitters_workshop2.pdf, retrieved on July 23, 2010.

13. V. Vijayan, Numerical model development of a heavy mining vehicle multi-piece wheel assembly for structural analysis, M.A.Sc. thesis, University of Windsor, October 2008.

14. R2900G LOAD HAUL DUMP Machine Safety, Excerpted from Operation & Maintenance Manual ((SEBU7333-00), 2007, Caterpillar Corp.

15. “Serve multi-piece and single piece rim wheels”, Standard Number 1910.177. Occupational Safety & Health Administration, Department of Labor, USA.

16. Society of Automotive Engineers (1993) Wheel Cornering Fatigue Test Standard – SAE J1992 Nov93, SAE Handbook, 2000, 400 Commonwealth Drive, Warrendale, PA.

Thank you! May we answer any questions?

University of Windsor

Weldon Li Aleksander Tonkovich li12c@uwindsor.ca tonkovi@uwindsor.ca

Sante DiCecco William Altenhof dicecco@uwindsor.ca altenh1@uwindsor.ca

Richard Banting RickBanting@workplacesafetynorth.ca

Workplace Safety North