Search

During the tests on the U.S.S. PRESTON, a great number of strain readings were taken at designated stations throughout the ship. To determine the true stress developed in the metal at these strain gage stations, it is necessary to know the true modulus of elasticity of the metal under strain. For this reason sample pieces were taken from the ship and tests were conducted for the purpose of determining this modulus of elasticity. (Author)

The paper presents the results of a preliminary investigation of the effect of stress intensity on the modulus of elasticity of concrete. Stress-strain diagrams are shown which were constructed for static tests and by using the vibratory data for transverse resonant vibrations at various stress intensities. The various tests were performed on the same cylinders, thereby using the same specimen for both the vibratory and static tests. The vibratory test is an adaptation of ASTM C215-60 with the specimens vibrated in their transverse mode. (Author), Presented at the Corp of Engineer Division Laboratories' Conference (1964), held at Boston, Mass., on 18 Nov 64.

The natural frequencies of a thin, isotropic, simply supported rectangular plate of constant thickness with sides a and b is discussed. The modulus of elasticity of the plate material varies with time. Assuming that the hypothesis on the preservation of normals is valid, and taking into account the inertia forces of the plate, a second-order differential equation is written (in accordance with S. P. Timoshenko's theory) which describes the free vibration of the plate under discussion. A solution of this equation, analogous to that used by the author in investigating the vibration of a thin plate in a high-temperature field, is written which is correct only for certain instants during vibration., Edited trans. of Akademiya Nauk Armyanskoi SSR, Erevan. Izvestiya. Mekhanika, v20 n4 p3-5 1967, by D. Koolbeck.

Vertical cracks normal to the major axis of a standard fire brick will cause a lowering of the dynamic modulus of elasticity calculated.

The effect of heat treatment of Ti-Al alloys of constitution near to that of Ti3Al and contg. 15.9 and 16.6 percent Al by wt. on their mech. properties were studied. The modulus of elasticity E and the modulus of transverse elasticity G were detd. by the resonance method. The specimens were annealed at 600 degrees for 200 hrs., then were heated in sealed quartz ampuls at 800, 900, 1000, 1100, 1150, 1200, and 1300 degrees for 48, 24, 18, 3, 2, 1, and 0.4 hrs., resp., and quenched in water. The results obtained show the continuous decrease of E and G, as the quenching temps. increase in the range of 900-1100 degrees for 15.9 percent and 900-1150 degrees for 16.6 percent Al. Further increasing of these temps. caused increase of E and G. Afterwards the specimen of 15.9 percent Al was quenched from 1100 degrees again and the effect of the duration of its tempering at 600, 700, and 800 degrees on the parameters investigated was studied. G and E increase only during the 1st 5-10 hrs. of tempering at 600-700 degrees. Further holding of alloy at these temps. did not affect these parameters. The tempering at 800 degrees caused increase of G and E only during the 1st 2 hrs. and further holding caused decrease of these parameters down to values for as-quenched state., Edited machine trans. of mono. Diffuzionnye Protsessy v Metallakh (Diffusion Processes in Metals), n.p., 1968 p110-113.