Abstract: A composite sheet has confined flexibility and is used in a safety pneumatic tire which is self-supporting under zero inflation pressure. The composite sheet comprises a matrix of high modulus solid objects, low modulus material, and optionally a matrix of cords, the high modulus solid objects being assembled to form a mechanism which allows the composite sheet to bend easily within predetermined ranges and confines the composite sheet from further bending when the limits of the predetermined ranges are reached. The safety pneumatic tire comprises a pair of the composite sheets disposed at sidewall regions under a carcass and/or a layer of the composite sheet disposed above a belt package. A method of making the composite sheet includes forming a chain of the high modulus solid objects having a desired locking position.