203 research outputs found
The dynamic analysis of piping systems using pseudo-dynamic techniques
This paper describes an application of pseudo-dynamic techniques to the dynamic analysis of
piping structures. Essentially it consists in coupling a direct time integration algorithm, such as the
Newmark method, to an experimental step. At each time step the integration algorithm generates a
displacement vector of the structure, which is prescribed for the test specimen. This is mounted in a rigid
test rig fitted with a set of displacement actuators and load cells at the level of the structure degrees of
freedom. The load cells allow the reading of the internal restoring force vector, which is fed back to the
direct time integration algorithm in an actual time step. Further calculations for the velocity and
acceleration vectors will define a new structure configuration by evaluating a new displacement vector
referred to the next time step. This procedure makes it possible to assess experimentally a realistic stress
distribution at sections of complex shape piping parts. The method is a precise tool in dynamic analysis
and, on being carried out in a quasi-static procedure, it operates with less expensive equipment than is
necessary in real dynamic test
Fungos micorrízicos arbusculares em bananeiras cultivadas no Vale do Submédio São Francisco
Population structure of the crab Callinectes ornatus Ordway, 1863 (Brachyura: Portunidae) bycatch in shrimp fishery in northern Rio de Janeiro state, Brazil
Influência da temperatura e da quantidade de água no substrato sobre a germinação de sementes de Ochroma pyramidale (Cav. ex Lam.) Urban (pau-de-balsa)
Shell occupation by the hermit crab Dardanus insignis (Decapoda, Diogenidae) from the north Coast of São Paulo state, Brazil
New insight on the underdrawing of 16th Flemish-Portuguese easel paintings by combined surface analysis and microanalytical techniques
Ecological distribution and population structure of Acantholobulus schmitti (Rathbun, 1930) (Crustacea, Decapoda, Xanthoidea) on the southeastern Brazilian coast
Relação umidade versus resistência à penetração para um argissolo amarelo distrocoeso no recôncavo da Bahia
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