996 resultados para Transportation Test Center (U.S.). Rail Dynamics Laboratory.


Relevância:

100.00% 100.00%

Publicador:

Resumo:

"DOT-T-94-19."

Relevância:

100.00% 100.00%

Publicador:

Resumo:

"HRDI-04/08-05(1M)E"--P. [4] of cover.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

"July 1991."

Relevância:

100.00% 100.00%

Publicador:

Resumo:

"June 1961."

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Compilers: 1964-1980, V. Haviland (with L. B. Watt, 1964-<1974>)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Shipping list no.: 97-0029-P.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Cover title.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

National Highway Traffic Safety Administration, Office of Driver and Pedestrian Research, Washington, D.C.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

National Highway Traffic Safety Administration, Office of Research and Development, Washington, D.C.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Urban Mass Transportation Administration, Washington, D.C.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

"May 1984."

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fruitful research on durability of paving asphalts may come from two approaches: The improvement of the asphalt for durability; The development of relatively rapid laboratory tests which will enable the design engineer to select or to specify an asphalt based on quality and to make a correct estimate of the service life of a selected asphalt when used in a specific paving mixture. Research Project HR-124, "Development of a Laboratory Durability Test for Asphalts," sponsored by the Iowa Highway Research Board is in the second category and was intended to be the initial stage of an overall study in the development of a durability test for paving asphalts.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Many researchers in the field of civil structural health monitoring (SHM) have developed and tested their methods on simple to moderately complex laboratory structures such as beams, plates, frames, and trusses. Fieldwork has also been conducted by many researchers and practitioners on more complex operating bridges. Most laboratory structures do not adequately replicate the complexity of truss bridges. Informed by a brief review of the literature, this paper documents the design and proposed test plan of a structurally complex laboratory bridge model that has been specifically designed for the purpose of SHM research. Preliminary results have been presented in the companion paper.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A study on the reproductive biology of Amblema neislerii, Elliptoideus sloatianus, Lampsilis subangulata, Medionidus penicillatus, and Pleurobema pyriforme was conducted from May 1995 to May 1997. The objectives of this study were as follows: 1) determine period of gravidity for each of the five mussel species, 2) determine host fish via laboratory experiments, 3) test whether unionid glochidia will transform on a nonidingenous fish, and 4) describe the glochidial morphology for each of the five mussel species using a scanning electron microscope. Amblema neislerii are tachytictic breeders and were found with mature glochidia in May. Elliptoideus sloatianus are tachytictic breeders and were found with mature glochidia from late February to early April. Lampsilis subangulata are bradytictic breeders and were found with mature glochidia from December to August. Superconglutinates were released by L. subangulata from late May to early July. Medionidus penicillatus are bradytictic breeders and were found with mature glochidia in November and February to April. Pleurobema pyriforme are tachytictic breeders and were found with mature glochidia from March to July. The following fish species served as hosts for A. neislerii: Notropis texanus, Lepomis macrochirus, L. microlophus, Micropterus salmoides, and Percina nigrofasciata. The following fish species served as hosts for E. sloatianus: Gambusia holbrooki, Poecilia reticulata, and P. nigrofasciata. The following fish species served as hosts for L. subangulata: G. holbrooki, P. reticulata, L. macrochirus, Micropterus punctulatus, and M. salmoides. The following fish species served as hosts for M. penicillatus: G. holbrooki, P. reticulata, Etheostoma edwini, and P. nigrofasciata. The following fish species served as hosts for P. pyriforme: Pteronotropis hypselopterus, G. holbrooki, and P. reticulata. Poecilia reticulata, a nonindigenous fish, served as a host for E. sloatianus, L. subangulata, M. penicillatus, and P. pyriforme. (76 page document)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

As we all know, rock-like materials will absolutely show very different mechanical properties under the compressive stress and tensile stress respectively. Similarly, under the dynamic compressive stress or dynamic tensile stress, the characteristics of the dynamics showed by the rock-like materials also have great differences from the mechanical behavior under static force. Studying their similarities and differences in rock mechanics theory and practical engineering will be of great significance. Generally, there are compression modulus of elasticity and tensile modulus of elasticity corresponding to compressive stress state and the tensile stress state in the rock. Both the two kinds of elastic modulus play an extremely important role in calculation of engineering mechanics. Their reliability directly affects the accuracy and reliability of the calculation results of internal stress field and displacement field of engineering rock mass. At present, it is easy to obtain the compression modulus of elasticity in laboratory; but it is very difficult to determine the tensile modulus of elasticity with direct tensile test due to that direct tensile test is difficult to perform in laboratory in general. In order to solve this problem, this thesis invents and develops several indirect test methods to determine the static or dynamic tensile modulus of elasticity of rock-type materials with high reliability and good interoperability. For the static tensile modulus of elasticity, the analytical stress field solution has been given out for the Brazilian disc under the radial and linear concentration load with Airy stress function method. At the same time, the stress field has been modeled for the Brazilian disc test by using the finite element software of ANSYS and ADINA. The analytical stress field solution is verified to be right by comparatively researching the analytical stress field solution and the numerical stress field solution. Based on the analytical stress field solution, this thesis proposes that a strain gauge is pasted at the Brazilian disc center along the direction perpendicular to the applied force to indirectly determine the static tensile modulus of elasticity, and related measurement theory also has been developed. The method proposed here has good feasibility and high accuracy verified by the experimental results. For the dynamic tensile modulus of elasticity, two measuring methods and theories are invented here. The first one is that the Split Hopkinson Pressure Bar is used to attract the Brazilian disc to generate the dynamic load, make the dynamic tensile stress is formed at the Brazilian disc center; and also a strain gauge is pasted at the Brazilian disc center to record the deformation. The second is that, in the Hopkinson effect phenomenon, the reflection tensile stress wave is formed when the shock wave propagates to the free end of cylindrical rock bar and reflect, which can make the rock bar is under dynamic tensile stress state; and some strain gauges are pasted at the appropriate place on the rock bar to record the strain coursed by the tensile or compressive stress wave. At last, the dynamic tensile modulus of elasticity can be determined by the recorded strain and the dynamic tensile stress which can be determined by related theories developed in this thesis.