Hi,<\/p>\n
I am having difficulties on correlating the axial stiffness of a simple cube between a modal and a static structural analysis.<\/p>\n
I am analyzing the cube shown below, that has the following properties:<\/p>\n
Cube Length L = 10 mm, Elastic Modulus E = 1050 MPa, Density rho = 7850 kg\/m^3, Normal displacement fixed at one side.<\/p>\n
According to theory, the stiffness is equivalent to K = E A \/ L = 1.05E4 N\/mm, where A = L^2 = 100 mm^2. The axial natural frequency of the cube is then equal to: f = 1\/(2*pi())*sqrt(K\/M), where M is the mass of the cube (0.00785 kg). The axial natural frequency is then calculated as 5821 Hz. However, according to modal analysis results, the axial natural frequency is way higher, f = 8948 Hz.<\/p>\n
For this reason, I have performed a static analysis to check the stiffness of the cube by applying a unit force at one face. The obtained displacement (u = 9.52E-5 mm), confirms an axial stiffness K = F\/u = 1.05E4 N\/mm. Please note that for static analysis convergence, I have fixed the displacement of one vertex on the fixed displacement side.<\/p>\n
Could you please help me understand what I am doing wrong in such a simple simulation?<\/p>\n
Thank you in advance.<\/p>\n
![\"\"](\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/07\/15-07-2024-1721053631-Stiffness.jpg\")
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