The braking system is one of the most important components of a vehicle. Without reliable brakes, drivers cannot safely stop, increasing the chances of an accident. Proper vehicle maintenance includes checking the brake pads and shoes, and replacing them as necessary. When buying brake disc pads and shoes, buyers should have a basic understanding of how brakes work, as well as the important differences between disc and drum brakes. Understanding How Brakes Work When drivers press the brake pedal, they engage the hydraulic system. This system forces fluid through a series of tubes and hoses that run from the brake's master cylinder to the piston, which applies pressure to the wheels and stops the car. Some brakes use a system of discs and brake pads to accomplish this, while others use shoes and drums. Most passenger vehicles have a combination of disc and drum brakes, with disc brakes attached to the front wheels and drum brakes attached to the rear wheels. Disc Brake
The goal of this study is to investigate the effectiveness of Composite Metal Foam (CMF) armors against 0.50 caliber ballistic threats. A hard armor was manufactured using a sandwich panel construction consisting of a ceramic faceplate, a CMF core, and a thin aluminum back plate. The hard armor system was tested against 0.50 caliber (12.7 × 99 mm) ball and armor piercing (AP) rounds. The CMF armors were tested with a variety of areal densities at impact velocities between 500 and 885 m/s. The armors stopped the threats at speeds up to 819 m/s without penetration. The CMF layer was found to absorb 73–76% and 69–79% of the kinetic energy of the ball and AP round respectively. When compared to rolled homogeneous steel armor (RHA), the CMF hard armors, in their current unoptimized condition, have a mass efficiency ratio of approximately 2.1. The CMF armor offers a much needed weight savings without sacrificing protection. Finite element analysis was completed using ANSYS/AUTOD