. The strength of materials; a text-book for engineers and architects. fcJD > o ffl 00 THE TESTING OF MATERIALS 365 A horizontal lever A, Figs. 158, 159, is provided with aknife-edge b resting upon a strong vertical frame v; a jockey-weight w is movable along this lever and carries a vernierR by means of which the position of the weight can be readoff upon a scale q. A second knife-edge c, carried by the lever, engages a linko connected to a cross-head. When operating for tension,one end of the specimen e is gripped in this cross-head, the. s ZD r^ 7 irnr H K L m-. z^ , < G G r 1 Fig. 15
. The strength of materials; a text-book for engineers and architects. fcJD > o ffl 00 THE TESTING OF MATERIALS 365 A horizontal lever A, Figs. 158, 159, is provided with aknife-edge b resting upon a strong vertical frame v; a jockey-weight w is movable along this lever and carries a vernierR by means of which the position of the weight can be readoff upon a scale q. A second knife-edge c, carried by the lever, engages a linko connected to a cross-head. When operating for tension,one end of the specimen e is gripped in this cross-head, the. s ZD r^ 7 irnr H K L m-. z^ , < G G r 1 Fig. 159. Sf^ecimen other end being gripped in a cross-head l connected by rods G to an hydraulic ram F. If the resultant of the jockey-weight w and the lever A is W and acts at a distance y from the knife-edge B, we have by moments V .X = W 2/ X The scale Q is graduated so as to read off values of P direct,because W and x are of fixed value. Stops s are provided for the lever a, which normally rests 366 THE STRENGTH OF IVIATERIALS on the lower one; as the pressure in the ram is increased theforce exerted upon the specimen gradually increases until itreaches the value P, Avhereupon the lever rises and floats between the two stops. A lower cross-head j is suspended from the cross-head H byrods K and is used for compression and bending tests. Thediagram on the right-hand side of Fig. 159 shows how the forceis applied in the case of a compression test. In a bendingtest the arrangement is similar, but the test-beam is placed onsupports on the cro
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyorkdvannostran
