The clutch is a mechanical device that engages and disengages power transmission from the engine to the wheels. It consists of the clutch disc assembly and cover assembly. The clutch disc, with friction material linings, is mounted on the transmission shaft and gets clamped between the flywheel and cover assembly to transmit power as required. However, wear and tear occur due to the differential speeds and slippage between the engine and transmission during operation.
Clutch performance is assessed for its thermal behavior under repeat restart conditions on steep gradients, which is essential for the reliability and durability of commercial vehicle clutches. Repeat restart test is a key test to assess clutch performance on a 12% gradient. This test replicates real world scenarios, such as truck launches on hilly terrains under full load, where the clutch experiences significant slippage due to speed differences. This generates heat, and repeated engagements can cause the temperature to rise, potentially leading to friction material wear and clutch failure if critical temperature thresholds are exceeded.
To overcome the time and cost challenges of traditional physical testing, a 1D simulation based approach has been developed using GT (Gamma Technologies) Suite software. This simulation models the thermal behavior of the clutch system under repeat restart conditions, incorporating driver inputs and drive cycles. The model simulates 90 repeat cycles of vehicle launches on a 12% gradient in first gear, predicting clutch housing air temperatures accurately.
This simulation methodology has a near 95% correlation with physical test data, validating its reliability. It allows early-stage design validation and optimization of parameters affecting heat generation and thermal degradation, reducing dependency on expensive physical trials and accelerating design iterations.
The GT model has been applied to analyze clutch thermal performance in 28-ton concrete transport vehicles. By predicting thermal behavior early in the design phase, engineers can avoid costly late-stage modifications. Furthermore, this methodology allows for design of experiments to evaluate the influence of drivetrain parameters and to select optimal configurations that reduce thermal stress on the clutch, improving overall system robustness. The adoption of GT Suite as a digital validation tool enhances the product development process by enabling faster, data driven decision making, reducing warranty costs, and ensuring better product quality. In a competitive market landscape, this virtual validation approach provides a strategic advantage by facilitating timely and efficient product launches.