Modeling, and FEA of Multi-Plate Clutches by Varying Materials for Optimum Torque Transfer Capacity of TCT System of Green, And Light Vehicles

This paper addresses Modeling and analysis of easily applicable multi-plate clutches to use in twin clutch transmission (TCT) system for green and Light Weight Vehicle. The static and dynamic analysis were developed for a clutch plate by using finite element analysis (FEA). The 3D solid model was done using SOLID WORK 2016 and imported to ANSYS work bench 16 for model analysis. The mathematical modelling was also done using different vastly available materials (i.e. Aluminum alloy 6061, E-Glass Epoxy, and Gray Cast iron); then, by observing the results, comparison was carryout for materials to validate better lining material for multi plate clutches using ANSYS workbench 16 and finally concluded that composite material E-Glass Epoxy has a better friction material for design of multi-plate clutches in TCT system.


INTRODUCTION
Clutches are projected for transferring the greatest amount of torque with less heat generation and is one part of the transmission system. Twin clutch transmissions (TCT) have emerged as a viable alternative to conventional planetary automatics and continuously variable transmissions with the development of precise control strategies. TCT can be considered as two lay shaft transmissions in one, Odd gears are connected to first shaft while the even gears are connected to the other shaft. Light Weight and Green Vehicles that use TCT has developed be an excellent and competitive in every situation [1].
Multi-plate clutches in a twin clutch transmission system are the most efficient and to be employed in vehicles to achieve better vehicle fuel economy and comfort. Vehicles that use a manual clutch has not been the preferred choice; due to recently developed automatic twin clutch transmission. Evidences show that racing cars, most electric vehicles, Honda cars and motorcycles have been available with automatic transmission systems [2]. The idea behind automatic Twin-clutch is that a vehicle requires less driver input for any transmission system. The TCT as its name implies uses two clutches to change gears. The transmission can be used in fully automatic mode, with a computer determining gear shifts. TCT, is available both in Wet and dry type Twin clutch transmission system, is more preferable, and has been developed to meet the very high torque capacity and to have more efficiency. Comparison of Wet, and Dry type clutches with their advantages and disadvantages has been done in [3,[5][6][7][8]. Good Characteristics of Clutches with high torque capacity, low weight, easy packaging, less noise, vibrations and Harshness (Good NVH characteristics), Longlife and High energy density as described in [4] II.
MATERIAL OF MULTI-PLATE CLUTCH To specify and limit number of materials to be used for the clutch analysis have be done by comparison of some material properties; Material selection property is used for the expected clutch disc materials and its mechanical property mostly used by different literatures.

III. NUMERICAL OF ANALYSIS
The numerical analysis of the TCT multi plate clutch was done in which theapplied force can keep the members together with a uniform pressure all over its contact area and the consequent analysis is based on uniform pressure condition. However as the time progresses some wear takes place between the contacting members and this may alter or vary the contact pressure appropriately and uniform pressure condition may no longer prevail. Hence the analysis was calculated based on uniform wear condition and uniform pressure theory. The maximum torque which can be transmitted by the friction clutch for uniform pressure theory is given bythe formula in equation1.
Where Rand r are external and internal radius of the clutch respectively.

International Journal of Advanced Engineering Research and Science (IJAERS)
[ The Constrained equation also formulated in equation 4, if the constraint equation j g in equation 4 is satisfied with a probability j p then the normal variation for probability j p is given then, the new constraint equation in deterministic form is given in equation. And finally problem reduces to minimize the objective function given by equation (2) satisfying constraint equation (4).
To design the multi plate friction clutch for maximum torque transmitting capacity, given by equation 1 and 2 can be calculated from a given values i.e.µ= 0.48, n=1, Hence the problem reduces to minimize objective function given by equation (4) satisfying constraint equation (5). If the torsion is only considered as active constraint then the degree of difficulty will be zero. The number of friction surfaces,since there are two multi plate clutches the number of friction surface is (n + n -1) which is 1; then the maximum torque increased n times. So, to deliver 5KW power, 135Nm torque, at a speed of 1000-5000rpm, using the candidate materials, design calculations include, Let's use the power delivery of the vehicle as 5KW and at a specified initial speed of 5000rpm. But the torque transferred by the clutch would be calculated for analysis of loads and maximum pressure with new specifications. So, using twin multi-plate clutch is using the number of friction surfaces to be one. Then, the total torque transfer would be; . 2 60  P t   (6) Where Tt = a total torque transfer, P = a maximum power carried by a clutch,  = speed in rpm Then using eq.6 above; Then, using the number of friction surfaces n=1: T = Tt/n = 10/1 = 10Nm (7) Now, from uniform wear theory, the clumping force W W = 2 π (Pmaxx D1) x (D2 -D1)  /dx.doi.org/10.22161/ijaers.5.1.17  ISSN: 2349-6495(P) | 2456-1908(O) www.ijaers.com Page | 117 The maximum pressure obtained by numerical analysis as  tabulated in table 4 was applied on the friction plate and results were obtained in Ansys work bench and stress and deformation values in figure -----are compared for the said materials. Figure 1 shows that the exploded and the meshed model of the plate. The boundary condition and load of the plate is applied as depicted in figure 2 below like applied the pressure and fixed supports.  /dx.doi.org/10.22161/ijaers.5.1.17  ISSN: 2349-6495(P) | 2456-1908(O) www.ijaers.com Page | 118

IV. RESULTS AND DISCUSSIONS
The same case for dynamic analysis was done and the static and dynamic analysis of external spline values are tabulated in the table 5 and 6 respectively. The above analysis is the external spline friction material for different candidates of material, in the same case the internal spline of friction material will analyzed both static and dynamic once. From figure 6 - figure 9 shown the static analysis of internal spline for aluminum alloy, gray cast iron and E-glass Epoxy using Ansy workbench. In same manner dynamic analysis is tabulated below.   .org/10.22161/ijaers.5.1.17  ISSN: 2349-6495(P) | 2456-1908(O) www.ijaers.com Page | 120 compared to the theoretical calculations. E-glass Epoxy UD has the low total deformation when compared to the existing conventional Gray Cast Iron friction material. Hence, it is concluded that E-glass Epoxy UD serves as a better friction material than Gray Cast Iron, and aluminum alloy and gives better clutch performance.
V. CONCLUSION From the ANSYS Workbench structural simulation and analysis in FEM is a key to facilitate the assessment of structural analysis of clutch plate which provides relatively simple method for analyzing of material strength. Besides, the analysis shows that increase in tensile yield strength of material, the maximum equivalent stress decrease and similarly the deformation rate decreases. The final result shows that E-Glass Epoxy materials have minimum deformation in their applied load and pressure conditions than other materials used, it also have high wear resistance property and lower weight than existing Gray Cast Iron, and aluminum alloy materials. Besides these, the weight of E-Glass Epoxy material is 72% lower than that of Gray Cast Iron and 26% lower than Aluminum Alloy Materials. So, this makes Epoxy Materials to be better for clutching.