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A multi-scale framework for designing green tyres

Primary Information

Domain

Advanced Materials

Project No.

7772

Sanction and Project Initiation

Sanction No: F.No.41-2/2015-T.S.-I (Pt.)

Sanction Date: 09/01/2017

Project Initiation date: 16/02/2017

Project Duration: 36

Partner Ministry/Agency/Industry

Ministry of Road Transport and Highways; MRF Limited Chennai;

 

Role of partner:Manufacture, testing and benchmarking of the green tyre will be carried out by MRF Limited (R&D lab) in Chennai.

 

Support from partner:MRF Limited, the industrial partner in the project, will support in design, manufacture and field testing of the green tyre.

Principal Investigator

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Krishna Kannan
Indian Institute of Technology Madras

Host Institute

Co-PIs

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Narasimhan Swaminathan
Indian Institute of Technology Madras

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Manoj Pandey
Indian Institute of Technology Madras

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Sundararajan Natarajan
IIT Madras

 

Scope and Objectives

Scope: Manufacture of green tyre with reduced rolling resistance compared to the existing tyres without compromising on the wet traction and wear performance.

Objectives:
1. To identify appropriate polymer and filler (BR/SBR and silica) combinations using molecular dynamics (MD) simulations and experiments.
2. To develop constitutive equations for the selected material and validate it.
3. To implement the developed constitutive equations in a commercial Finite Element software to allow the design and analysis of a green tyre.

Deliverables

Main Deliverables: 1. Selected material combination for the green tyre. 2. Validated constitutive equations. 3. Tested element and material subroutines.

 

Project image

Scientific Output

1. The strength of the interface formed between the filler and the tire polymer is studied by means of computational approach. The methodology to evaluate polymer and filler (BR/SBR and silica) combinations using molecular dynamics (MD) simulations and experiments is identified.
2. Combinations of identified functionalizations are being evaluated for good interfacial strength through MD simulations using LAMMPS.
3. A new compressible rate-type viscoelastic constitutive model with limiters on dilatation, contraction, and distortion for carbon black filled rubber is developed using a thermodynamic framework. Experimental data obtained from in-house tests are used in validating the derived continuum model.

 

Results and outcome till date

Activity 1 - Material Identification for Green Tyres: A set of pull-out tests were conducted at 300 K in order to further investigate the effectiveness of the identified silane coupling agent, APTS with the commercially used TESPT. The results of these pull-out tests will be compared with the results obtained for pull-out tests at 1 K. Three combination of silane coupling agents were used. Pure TESPT, pure APTS and a combination of TESPT and APTS in equal ratio. The identified SBR combination S1 containing 51 percentage styrene was used as the polymer bulk. This polymer bulk was cross-linked with monosulphidic bridges inside the rubber matrix. Sulphidic bridges between the polymer chains increases the strength of the rubber matrix. The maximum strengthening effect is for the monosulphidic bridges. The analysis tools, bound polymer and strength modulus were obtained for three combinations. The trends obtained at 1 K was different from the trends obtained at 300 K. Activity 3 - Constitutive modelling of large-scale response of material: The algorithmic implementation of the developed viscoelastic model into the commercial finite element package Abaqus Explicit through VUMAT, is ongoing. The code is now tested and some of the routines are changed to make it robust for solving large scale IBVPs. The developed model has an evolving state variable, which happens to be the solution of an implicit ordinary differential equation. Along with the equation of state, the constitutive equation for Cauchy stress is prescribed as well. The spatial solution for displacements are sought by solving the balance of linear momentum with the constitutive model embedded within by rewriting the differential equation as an integral equation. Along with the right boundary conditions, the set of equations are solved numerically and approximate solutions are obtained.

 

Societal benefit and impact anticipated

1. In electric (EV) and gasoline vehicles, RR consumes about 25% of the power supplied to the wheels. Reducing RR from 25% to 20% will improve range by 5%.
2. Estimated 12 million tons of CO2 per year emitted by automobiles (10% of total fuel consumption) is attributed to Rolling Resistance whose root cause is the dissipation in tyres. Reducing RR from 10% to 7.5% results in CO2 reduction by 3 million tons/year.

Next steps

A methodology to implement the developed constitutive equations as a plugin to ABAQUS commercial software using UMAT feature is developed.
1. Testing of the implementation of sub-routines for simple deformations using existing models is in progress.
2. Numerical simulations of large-scale response of the selected material for green tyre and their validation through experimental data are planned to ensure the final outcome which is the manufacture of the new green tyre with lower RR compared to existing tyres without compromising on other performance measures.

Publications and reports

Devendiran, V. K., Mohankumar, K. V., Kannan, K., Varkey, B. T., 2019. Validation of a thermodynamically consistent compressible rate-type viscoelastic model with independent limits on dilation, contraction, and distortion. Int. J. Non-Linear Mech., 116 (2019), pp. 85-101 (doi: 10.1016/j.ijnonlinmec.2019.06.002)

Patents

None.

Scholars and Project Staff

Tenure of one Post doctoral fellow is extended.

Challenges faced

Matching fund associated with the second installment is yet to be received from the Ministry of Road Transport and Highways.

Other information

none

Financial Information

  • Total sanction: Rs. 12973000

  • Amount received: Rs. 8927500

  • Amount utilised for Equipment: Rs. 3984743

  • Amount utilised for Manpower: Rs. 1222575

  • Amount utilised for Consumables: Rs. 1069122

  • Amount utilised for Contingency: Rs. 489635

  • Amount utilised for Travel: Rs. 79646

  • Amount utilised for Other Expenses: 0

  • Amount utilised for Overheads: Rs. 1487114

Equipment and facilities

 

none