Vibrations produce forces that change in amplitude and Direction with a definite frequency or range of frequencies. goods are subjected to vibration caused by engines or road vehicles, propellers of ships or aircraft, impacts from road or rails and handling equipment. Vibration may damage or loosen screws, parts of machinery items cause loosening of electrical contacts and the consequent sparking or leakage of current, seriously impair electronic items like calculators, or even cause structural failure in packaging materials.