Презентация на тему: " COPYRIGHT DASSAULT SYSTEMES 20021 Generative Part Structural Analysis CATIA Training Additional Information Version 5 Release 8 March 2002 EDU-CAT-E-GPS-FO-V5R8." — Транскрипт:
COPYRIGHT DASSAULT SYSTEMES Generative Part Structural Analysis CATIA Training Additional Information Version 5 Release 8 March 2002 EDU-CAT-E-GPS-FO-V5R8
COPYRIGHT DASSAULT SYSTEMES Table of Contents Hanger Analysisp.4 Static Analysis p.5 Frequency Analysisp.6 Buckling Analysisp.7
COPYRIGHT DASSAULT SYSTEMES Hanger Analysis In this lesson, we will interpret results from static, frequency and buckling analysis. Static Analysis : Stresses and displacements analysis Frequency Analysis : Frequency results analysis Buckling Analysis : Buckling Load Factors analysis
COPYRIGHT DASSAULT SYSTEMES Static Analysis There are two main objectives : minimize max stress and/or max displacement. These quantities can be visualized on nodes or on elements (Average/Discontinuous Visu options). 1. Von Mises result 1. Von Mises result : Its the most used stress state indicator (for ductile materials, like aluminum and steel). Here, the max stress value is 61.7 MPa which is less than the 95 Mpa tensile yield strength : the part is deformed elastically. 2. Full stress tensor result 2. Full stress tensor result : We can visualize normal (C11, C22, C33) and shear stresses (C12,…), which must be less than respectively the tensile and the shear Yield Strength. Here, shear stresses, so twisting effects, are not predominant (compare to bending effects). 3. Principal stresses result 3. Principal stresses result : We can see the pure tension and compression effects (by convention, C1>C2>C3). Here, the upper face is submitted to pure tension, whereas the bottom area shows compression effects. 4. Displacements 4. Displacements : We can check if the displacement amplitude at the front area is not too important (overcrowding problems).
COPYRIGHT DASSAULT SYSTEMES Frequency Analysis We can perform a frequency analysis or a free-frequency analysis, if the part is clamped or not. We will access to the natural frequencies and the mode shapes. 1 st mode 2 nd mode 3 rd mode 4 th mode 5 th mode 6 th mode Notice that displacements values are not real, and only the shape is to take into account. A modal analysis is often done if the not-random forcing frequency is more than one-third the structures fundamental frequency. The natural frequency is function of the Stiffness/Mass ratio. 2. Apply clamps and 5Kg distributed mass 2. Apply clamps and 5Kg distributed mass : So as to be closer to reality. 3. Results 3. Results : We have access to natural frequencies (fundamental and harmonics) of the geometry, which only depend on the mass and the rigidity, and the mode shapes for a given mode (combination of bending and twisting motions). 1. Choose a frequency analysis 1. Choose a frequency analysis : Prefer a Lanczos method which is very powerful.
COPYRIGHT DASSAULT SYSTEMES Buckling Analysis Parts which have one or several dimensions smaller than the others, and which are submitted to compressive loads, need Buckling Analysis. 1. Launch a linear Buckling Analysis 1. Launch a linear Buckling Analysis : Select the previous Static Case Solution. 2. Results 2. Results : We have access to Buckling factors for each modes, and the Buckling mode shapes (see below). Often, the first Buckling factor is to take into account : Here, we can apply a maximum load value of N without have Buckling instability problems. If a unit load is specified, the Buckling factors represent the Buckling loads. If the max stress is less than the yield strength, and if the Buckling Load factor is superior to 1, there will be no Buckling effects. 1 st buckling mode 3 st buckling mode 2 nd buckling mode 4 st buckling mode With 1000 N real load With unit load