Year of Publication
O. J. Hahn
Weftless bead design used in tires has long been the cause of failure. This type of bead design is generally used in agriculture, buses, trucks and passenger car tires. The main problem with this kind of bead is the splice region. It has ten cut wires, five at each over and underlap region. It is known since 1950 that Weftless design of the tire bead had failures within about 5 cm from the end of the overlapping parallel wire ribbon. The cause for this failure is generally attributed to the mounting process in which the diameter of the tire bead is changed during the mounting process as it moves from the well of the rim to the bead seat. The ideal bead design is a high strength flexible cable with minimal cross section, having same over and under windings to prevent stress concentrations in deflections as used in a normal steel cable. A finite element model of the tire bead was developed using ANSYS and tested under the known stresses of the mounting and final use conditions. Finite element calculations show the failure point of the Weftless bead is almost always at the under lap or at the starting point of this bead. Cable bead have significant advantages in safety over the Weftless bead still used in tires.
Khatra, Sandeep Singh, "LIMITATIONS OF WEFTLESS BEAD AND ITS COMPARISON WITH CABLE BEAD DESIGN FOR TIRES" (2004). University of Kentucky Master's Theses. 335.