| 释义 |
▪ I. ˈprestress, n. and a.
A. n. [pre- A. 2.] Tension applied to an object during manufacture or prior to some other treatment, usu. in order to counteract applied compressive loads (as in prestressed concrete).
1934Engineering News-Record 13 Sept. 345/1 A pre⁓stress of 8,392 lb. per sq. in. 1940Structural Engineer XVIII. 642/1 (heading) Diminution of the preliminary tensile pre-stress in steel by shrinkage and creeping. 1956Archit. Rev. CXIX. 146/3 Strips of shuttering supported on props are necessary under the transverse diaphragms and these also support the precast units before the pre⁓stress is applied. 1967New Scientist 10 Aug. 295/1 The higher the prestress applied, the higher the fatigue strength of the section. 1977Design Engin. July 64/1 Forces depend on prestress, i.e. initial deflection of spring, as well as direction of motion.
B. adj. [pre- B. 2.] Occurring before a stressed syllable.
1973Word 1970 XXVI. 98 In the traditional analysis long vowels occur only under stress... Therefore, no prestress vowel may be long. 1975Amer. Speech 1972 XLVII. 171 The sets of intersyllabic consonants and consonant clusters differ remarkably in different slots; for instance prestress /bh bt nk/ (as in abhór, obtáin, enquíre).
▪ II. prestress, v.|priːˈstrɛs|
[pre- A. 1.]
trans. To apply stress to (an object or material) prior to some other treatment; to introduce stress into (an object) during manufacture, so as to enable it more successfully to withstand applied loads; spec. with reference to reinforced concrete (cf. prestressed ppl. a.).
1934Engineering News-Record 13 Sept. 345/1 The idea of destroying the bond between steel rods inserted in concrete, and prestressing the rods in tension and the concrete in compression, is not new. 1936Structural Engineer XIV. 252/1 The concreting operation is carried out in the usual manner, the only difference being that the longitudinal rods are pre-stressed. 1940Concrete & Constructional Engin. XXXV. 330/1 Thin piano wires, of a strength of 350,000 lb. to 450,000 lb. per square inch, are prestressed to a stress equivalent to half that of yield point. 1967New Scientist 10 Aug. 295/1 When the concrete is prestressed the steel is dynamically opposed to the applied load. Ibid., Any series of units can be cast separately and then prestressed together to convert them into a monolithic whole. 1971Materials & Technol. II. iv. 113 (caption) The vertical outer wall..was prestressed with Freyssinet cables.
So preˈstressing vbl. n.
1934Engineering News-Record 13 Sept. 345/1 One advantage of the prestressing is to postpone the formation of cracks. 1940Structural Engineer XVIII. 629 Notwithstanding the cost of the pre-stressing operations, this great saving in materials renders also pre-stressed designs very economical. 1953Sci. News Let. 24 Jan. 63/2 In one phase of the study, it was found that prestressing doubled the ability of one aluminum alloy, used in the aircraft industry, to carry an external load. 1964C. W. Glover Structural Precast Concrete xix. 328 The basic idea of pre-stressing is to induce in the unloaded members stresses that are contrary to the stress normally produced by loading. 1974Encycl. Brit. Macropædia IV. 1078/1 The calculation of the initial tensile force required in the prestressing tendons to produce compressive stresses that will counteract the tensile stresses in the concrete. |