What is the most common lock up clutch design used heavy duty torque converter?

The most common lock-up clutch design used in heavy-duty torque converters is the multi-disc clutch. This design typically features several friction discs that engage when the clutch is activated, providing a direct mechanical connection between the engine and the transmission. This enhances fuel efficiency and reduces heat generation during operation. Additionally, the multi-disc setup allows for higher torque handling, making it suitable for heavy-duty applications.