A double-mass oscillator consists of two linear springs and masses, which are concentrated at the nodes. Vlastní tíha pružin je zanedbána. Determine the natural frequencies of the system.
Dvojhmotový systém se skládá ze dvou hřídelů a dvou hmot reprezentovaných příslušnými momenty setrvačnosti soustředěnými v dané vzdálenosti jako uzlové hmoty. The left shaft is fixed, and the right mass is free. Neglecting the self‑weight of the shafts, determine the torsional natural frequencies of the system.
Konzola s I-profilem je podepřena na levém konci a zatížena momentem. The aim of this example is to compare the fixed support with the fork support and to investigate the behavior of some representative quantities. Comparison is also made to the solution by means of plates. Small deformations are considered, and the self-weight is neglected. Determine the rotation in the midpoint of the cantilever, and in case of the member entity with warping, determine the values of the primary torsional moment, the secondary torsional moment, and the warping moment both on the left end (point A) and the right end (point B).
Časová analýza konzoly (SDOF - systém s jedním stupněm volnosti), která je buzena periodickou funkcí. Vertical deformations and accelerations calculated with direct integration and modal analysis in RF‑/DYNAM Pro - Forced Vibrations are compared with the analytical solution.
Verifikační příklad popisuje tlaková zatížení na stěny budov v tandemovém uspořádání na úrovni terénu. The buildings are simplified to rectangular objects and scaled down while maintaining the elevation ratios. The pressure distribution on the walls of the model of a medium-high building was conducted by an experiment. The chosen results (pressure coefficient Cp) are compared with the measured values.
Stanovte prvních šestnáct vlastních frekvencí dvojitého kříže se čtvercovým průřezem. Každé z osmi ramen je modelováno pomocí čtyř nosníkových prvků a má na konci čepovou podporu (průhyby x a y jsou omezené). Kmitání se zohledňuje pouze v rovině xy. Problém je definován podle normy NAFEMS Benchmarks.
Dvoupodlažní rámová konstrukce o jednom poli je vystavena seizmickému zatížení. The modulus of elasticity and cross‑section of the frame beams are much larger than those of the columns, so the beams can be considered rigid. The elastic response spectrum is given by the standard SIA 261/1:2003. Neglecting self-weight and assuming the lumped masses are at the floor levels, determine the natural frequencies of the structure. For each frequency obtained, specify the standardized displacements of the floors as well as equivalent forces generated using the elastic response spectrum according to the standard SIA 261/1.2003.
Verifikační příklad popisuje ustálené proudění okolo osamělé budovy (zmenšený model).Příklad je uveden od AIJ (Architectural Institute of Japan). The chosen results (velocity magnitude) are compared with the measured values.
A spherical balloon membrane is filled with gas with atmospheric pressure and defined volume (these values are used for FE model definition only). Determine the overpressure inside the balloon due to the given isotropic membrane prestress. K tomu slouží přídavný modul RF-FORM-FINDING. Elastic deformations are neglected both in RF-FORM-FINDING and in the analytical solution; self-weight is also neglected in this example.
A cantilever of rectangular cross‑section has a mass at the end. Kromě toho je zatížena normálovou silou. Calculate the natural frequency of the structure. Neglect the self‑weight of the cantilever and consider the influence of the axial force for the stiffness modification.
Hmotový systém s vůlí a dvěma pružinami se nejdříve vychýlí. Determine the natural oscillations of the system - deflection, velocity, and acceleration time course.
Verifikační příklad popisuje zatížení větrem v několika směrech proudění větru na modelu skupiny budov. The model consists of eight cubes. The velocity fields obtained by the RWIND simulation are compared with the measured values from the experiment. The experimental data are measured using a thermistor anemometer in the wind tunnel.