A Text-book on the Mechanics of Materials: And of Beams, Columns, and Shafts |
Common terms and phrases
angle applied bending bending moment cantilever beam cast iron cent coefficient of elasticity column compressive stress compressive unit-stress computed cross-section cylinder deduced deformation distance elastic curve elastic limit elastic resilience equal equation EULER'S formula experiments factor of safety feet long fiber flexure formula given gives hence hoop horizontal impact inertia internal stresses investigation left support length linear foot longitudinal material maximum unit-stress middle moment of inertia neutral axis neutral surface outer plane plates pounds per linear pounds per square pressure Prob produced R₁ radius ratio reaction required to find resistance revolutions per minute rivets rupture S₁ shaft shearing stress shearing unit-stress side simple beam specimen square inch steel Strength of Materials T₁ tangential tensile or compressive tensile strength tensile stress tension tests thickness tion torsion ultimate resilience ultimate strength uniform load uniformly velocity vertical shear weight wrought iron
Popular passages
Page 224 - ... unobserved, but resilience is not stress and there is no way in which they can be correlated except by combining the latter with the deformation that it produces. Keep's tables for impact are nothing more than the statement that the pressure produced by a blow is 5.42 pounds for each inch-pound of work, but it should be said that he fully regards this as arbitrary and valuable for comparative purposes only. These unnecessary paradoxes and misunderstandings can be dispelled only by a clear conception...
Page 165 - ... of iron, where the tensile strength was ascertained by direct experiment, it would appear that the ratio between the resistance of tension and the resistance of flexure varies in different qualities of metal, an inference which seems to be confirmed by other experiments on rectangular bars given in the Report of the Commissioners on the application of iron to railway structures.
Page 223 - ... brought to rest by a uniform resisting force in one second of time. The assumption that the pressure varies directly with the fall, or with the work done by the fall of the ram, has no reasonable basis at all. The correct principle here is, as well elucidated by Skinner in 1877, that the mean value of the pressure multiplied by the distance through which it...
Page 210 - ... mean proportional between twice the height of fall and the extension due to the same weight when applied gradually., while for vertical impact it is the sum of the static extension and the hypothenuse of a right angled triangle whose sides are this static extension and the dynamic extension stated for the horizontal bar. It is a corollary from this that under the sudden application of a load, which is the particular case of impact when the height of fall is zero, the maximum elongation and hence...
Page 43 - The moment of resistance of the bending (direct) stresses at any transverse section is equal to the algebraic sum of the moments of the external forces on either side of that section taken about the neutral axis in that section.
Page 51 - Inertia of a surface about an axis through its center of gravity und perpendicular to the surface is the sum of the products obtained by multiplying each elementary area by the square of its distance from the center of gravity of...
Page 49 - Fig. sof the stresses U, D and L hold in equilibrium the external forces on the left of the section cutting these members. These external forces consist of a left reaction, R, at u5 R, (b) the left abutment and a force at 2, equal to the reaction of the stringer 2-3. The resultant, S, of these two forces acts at a point a little to the left of the left reaction.
Page 6 - This lasting part of the strain is called a set, and in such cases the strain is not proportional to the stress. 4. Under a still greater stress, the strain rapidly increases, and the body is finally ruptured or broken. 5. A force acting suddenly, as a shock, causes greater...
Page 36 - uniform load' embraces the weight of the beam itself and any load evenly spread over it. Uniform loads are estimated by their intensity per unit of length of the beam, and usually in pounds per linear foot. The uniform load per linear unit is designated by w, then wx will represent the load over any distance x\ if / is the length of the beam, the total uniform load is wl, which may be represented by W. A ' Concentrated Load ' is a single applied weight and this is designated by P; a moving concentrated...
Page 216 - ... no valid numerical measure of the true ultimate resilience of the material. Our knowledge as to what occurs under such repeated impacts is of the most uncertain kind. Most of the stresses are no doubt injurious as the final result proves, but a few may perhaps be beneficial in improving the quality of the material like the process of cold-hammering and cold-rolling in manufacture. Baushinger's discovery in 1885, that the raising of the tensile elastic limit is accompanied by a lowering of the...