V tomto příkladu porovnáváme vzpěrné délky a součinitel kritického zatížení, které lze vypočítat v programu RFEM 6 pomocí addonu Stabilita konstrukce, s ručním výpočtem. Konstrukční systém je tuhý rám se dvěma přídavnými kloubovými sloupy. Tento sloup je zatížen svislými osamělými zatíženími.
A membrane is stretched by means of isotropic prestress between two radii of two concentric cylinders not lying in a plane parallel to the vertical axis. Find the final minimum shape of the membrane - the helicoid - and determine the surface area of the resulting membrane. 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 cylindrical membrane is stretched by means of isotropic prestress. Find the final minimal shape of the membrane - catenoid. Stanovíme maximální radiální průhyb membrány. The add-on module RF-FORM-FINDING is used for this purpose. Elastic deformations are neglected both in RF-FORM-FINDING and in the analytical solution; self-weight is also neglected in this example.
A cable is loaded by means of a uniform load. Výsledkem je deformovaný tvar kruhového segmentu. Determine the equilibrium force of the cable to obtain the given sag of the cable. The add-on module RF-FORM-FINDING is used for this purpose. Elastic deformations are neglected both in RF-FORM-FINDING and in the analytical solution; self-weight is also neglected in this example.
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.
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.
Ve spodní části jsou upevněny čtyři sloupy, které jsou nahoře spojeny tuhým blokem. The block is loaded by pressure and modeled by an elastic material with a high modulus of elasticity. The outer columns are modeled by linear elastic material and the inner columns by a stress-strain diagram with decaying dependence. Assuming only the small deformation theory and neglecting the structure's self-weight, determine its maximum deflection.
Stanovíme maximální průhyb čtyř dolních sloupů spojených tuhým blokem nahoře. The block is loaded by pressure and modeled by an elastic material with a high modulus of elasticity. The outer columns are modeled as orthotropic elastic material, and the inner columns as orthotropic elastic-plastic material with the same elastic parameters as the outer columns and plasticity properties defined according to the Tsai-Wu plasticity theory.