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A330 floor panels with cutouts substantiation
Well, from my knowledge the floor panels act as shear panels in the floor structure(crossbeams and stringers). In case of a load in FWD direction the crossbeams do not take any load, they just "bend", and that load is supported by these panels. I have to prove that the cutouts+reinforcement will...- brailos
- Post #4
- Forum: Aircraft engineering
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A330 floor panels with cutouts substantiation
Hello, Does anyone has experience in making a substantiation report regarding the creation of cutouts in a floor panel? I have a few ideas how to approach this presuming i have the data about the honeycomb core and the fasteners used to fix it to the floor. - Try to find the loads that the...- brailos
- Thread
- Replies: 4
- Forum: Aircraft engineering
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Element forces output - Sandwich honeycomb + FEM
Hello, I have a question for people who have experience with designing,calculating and testing honeycomb panels/structures. I want to know what are the steps in the Design process of a honeycomb sandwich panels structure. I have a structure subjected to a gravity load. I make an FEM model... -
Simply Supported and Clamped edges definition in FEM modelling
Hello , i would like to clarify some things. Perhaps you could help. I am trying to make some FEM analysis about some examples in Bruhn and BDM abou buckling of plates. I want to take those examples and compare the results obtained analytically with the ones form FEM. But i a have some... -
Help with contacts on Nastran 8 (UG-8)
Hello, Did you use Surface Contact mesh from FEM with CGAP elements or did you use Surface to surface contact from Simulation? I recommend trying with Surface contact mesh and see what happens. Be careful you have to edit the Contact mesh and define the initial gap opening and the other... -
Analyzing honeycomb panels structures
Well to size it for no failure at DUL is not that simple. I mean it is simple from a structural strength point of view, but the weight, costs and complexity of the structure would not make things feasible. The structure has to withstand the Ultimate load case for 3 seconds, even if it bends ... -
Analyzing honeycomb panels structures
Hello, I would like to hear some experiences of some of you guys with the design,analysis and testing of honeycomb structures. I am not interested in how to analytically analyze a rectangular panel or how to model it in FEM.....you can find that in every book. What i am interested is what are... -
Reading Axial loads from a FEM Model with gravity load
Hello, I have stumbled on a issue , regarding the design of sandwich honeycomb panel structures. I have no problems in designing and making the analysis for rectangular plates , as for Bruhn and BDMs are more then enough and clear, but as long as your inputs are known. My structure is a... -
Axisymmetric elements in NX Nastran 7.5
I am trying to make an axisymmetric mesh of a cylinder shape, very simple.I have the revolving section of the cylinder. Does anyone know how do you mesh that surface with axysimmetric elements like CQUADX4, 8 or CTRIAX3 or 6? Because i can fin these elements in the help manual describing their... -
Shell Surface-to-Surface (non-glue) Contact Issues
Did you defined the contact region surfaces manually or automatically? Did you defined the Global Contact Parameters in the BCTPARM / Case Control Tab? If not you have to define those parameters as the number of iterations, initial penetration etc... You might also try to reverse contact... -
Axisymmetric elements in NX Nastran 7.5
I am trying to make an axisymmetric mesh of a cylinder shape, very simple.I have the revolving section of the cylinder. Does anyone know how do you mesh that surface with axysimmetric elements like CQUADX4, 8 or CTRIAX3 or 6? Because i can fin these elements in the help manual describing their...- brailos
- Thread
- Replies: 0
- Forum: Siemens: UG/NX
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Nastran error-Too many restarts
29311 Iterative Solver - SITDR2, SOLVIT, ITER - UFM 6724 (SB1RM) The iterative solver may fail with the message: USER INFORMATION MESSAGE 6447 (SITDR2) ITERATIVE SOLVER DIAGNOSTIC OUTPUT EPS : 1.00000E-06 BICWELL... -
SPC Forces when running analysis with CGAP different then using RBE3
I believed that too..let me explain better. I have a big model with 4 shafts modeled with CGAP and CBAR, and today i realized the reactions are wrong.In that specific model CDITER was 40, but in the .f06 file all the subcases (12) are converging, it says that at the end of each subcase and they... -
SPC Forces when running analysis with CGAP different then using RBE3
UPDATE! Funniest thing happened, i kept trying changing parameters to see if anything affects the Reaction Forces, and i found out that by removing these parameters: CDITER: 40 (this alone changes things) CDPCH YES CDPRT NO GRDPNT 0 i get the correct reactions , plus the stress was at the... -
SPC Forces when running analysis with CGAP different then using RBE3
Hello everybody, I have a small problem using CGAP elements. I use NX 7.5 and trying to output the reaction forces but when summing up the forces i have they are not the same with the Loads. I am using CGAP elements in a linear analysis with SOL 101. Solution parameters used: AUTOMPC YES...
