STRUCTURAL CHARACTERISTICS OF SHEET METAL EMBOSSED WITH AN IRREGULAR DESIGN.

To reduce weight but not strength of structures, the use of sheet metal stiffened by an embossed design instead of heavier plain metal sheets is well known. The characteristics and the potential of a particular stiffened sheet were investigated. An L-shaped element dimple was chosen to be embossed in 0.062-inch-thick sheet metal in a multielement pattern. Under simple bending conditions, the substitution of dimpled sheets for plain sheets of the same stiffness realized a weight reduction of 18 to 59 percent. An equation for the deflection of the dimpled sheets could not be developed because there is no established theory to which the deflections would comply when the sheets were loaded to produce an anticlastic surface. The principal deficiency of the dimpled sheet is the anisotropic elastic properties that result from the pattern arrangement and discontinuity of the elements. Author