Certain characteristics of comsol become apparent with use. Can anyone help with boundary conditions in comsol near. But third principal stress in 2d are unrealistically high, however in 3d have value similar to the expected. This model is licensed under the comsol software license agreement 5. Note that while comsol employees may participate in the discussion forum, comsol software users who are onsubscription should submit their questions via the support center for a more comprehensive response from the technical support team. There exist a couple of particular angles where the strains take on special values. Then, change the contour type to filled and plot the graph. Use probe to determine that the minimum principal stress. This page performs full 3d tensor transforms, but can still be used for 2d problems enter values in the upper left 2x2 positions and rotate in the 12 plane to perform transforms in 2d. Click replace expression and select first principal stress. Contact comsol via the button below to evaluate the software.
Then, under the more plots button, add a maxmin volume plot and again replace the expression with the principal stress. Hi guys, i like to find a principal stress in my model. Dec 11, 2012 hi first to make your two models really identical, set the 2d depth to 0. What is the best way to start with comsol multiphysics. It is based on the first order shear deformation theory, which is a class of equivalent single layer theory, where all layers are aggregated into an equivalent material. For the first time, multiphysics simulations can now be integrated into the modeling of geometrical optics, a truly cuttingedge development for the simulation industry. Read more about all of the updates relating to studies and solvers below.
With the load increasing in magnitude in the positive direction, the maximum principal stress also starts to increase. Analysis of deformation comsol multiphysics modeling software. Dear all, i was trying to calculate the shear stress due to fluid flow inbetween two parallel plates from the velocity profile taken from the middle of the flow channel along vertical axis y using comsol. Comsol software users who are onsubscription should submit their questions via the support center for a more comprehensive response from the technical support team.
Postprocessing is used to create graphical displays that show the distribution of stresses, deformations, and other aspects of the. Hardness tests show trends similar to the hardening profiles that were created after the weld simulation. Comsol multiphysics results add 2d 3d plots, right click, go in to stress in lists. However, wed like to compare our results with our hand computation. Application builder launched with comsol multiphysics 5. Shown are the the first principal strain and the third principal strain, where the analysis indicates that the eyeglass frame will break in the thin section over the nose. I am also trying to obtain the longitudinal vibration modes of a very long cylinder. A simulation of the elastic regime was first performed by comsol in order to confirm that the stress field is uniaxial and homogenous along the operational length of the sample 31. So in this particular case, you can compare your tensile stress directly with that present in a normal tensile test. Introducing the composite materials module comsol blog. This may ultimately lead to a fatigue failure of the material.
When solid bodies are deformed, internal forces get distributed in the material. The blue square is oriented so that it matches the principal stretch directions. If you add a principal stress plot, you will see the names of the principal stress variables. Principal stresses create another plot to display the principal stresses in the bracket. Rather, than reading books on comsol, i suggest please start using comsol because when you will start, you will find many errors, may be physics. These variables are not visible in equation view since they are not computed by an explicit expression, but by solving an eigenvalue problem. Simulation results showing the sound pressure distribution in a loudspeaker driver enclosure. The principal stresses are the corresponding normal stresses at an angle. A static linear analysis 31 1 right click results to add a 3d plot group then rightclick the node and select more plots principal stress volume. So you really need three principal stress plots even in 2d. There are two main states in the conveying process, stationary and moving.
It can be observed that initially the load is in the downward direction and as it decreases in magnitude, the stress also reduces to a value of 0 at 0 load. Comsol multiphysics modeling environment with customized user interfaces and functionality. The output of a mathematical solver is generally a substantial quantity of raw data. So, i will add another plot group in which the first principal stress, sp1, is shown. In the figure below, the deformation is decomposed into a pure stretch and pure rotation. In his keynote talk at the comsol conference 2018 lausanne, andri bezzola of samsung presents case studies for how he uses the comsol multiphysics software and simulation applications to design high. Nov 12, 2009 dear all, i was trying to calculate the shear stress due to fluid flow inbetween two parallel plates from the velocity profile taken from the middle of the flow channel along vertical axis y using comsol. Jeanette littmarck has 25 years of sales experience at comsol and is the sales director for government accounts in washington, d. The 1st principal stress gives you the value of stress that is normal to the plane in which the shear stress is zero. In this stepbystep instructional video, you will learn how the solid mechanics interface in comsol multiphysics can help you solve structural mechanics. Paid classes for new and current users featuring live demonstrations, handson activities, and lectures.
The 3 principal stresses define the stress in this point respect the plane and his 3 direction. This is the logarithmic strain, or true strain, with orientations given in a spacefixed coordinate system, well suited for plotting on the deformed geometry in a. Both 2day intensive trainings and 1day specialized classes are available. The orientation of the first principal stretch axis is 58. A new set of principal strains have been added to the results in the solid mechanics interface. The maximum principal stress values of plagioclase and orthoclase are larger, indicating that they are likely to incur the least damage. Comsol multiphysics and the acoustics module the acoustics module, an addon product to the comsol multiphysics software, is ideally suited for modeling the many decades of frequencies involved in figure 2. The 1st principal stress helps you understand the maximum tensile stress induced in the part due to the loading conditions. With the composite materials module, the shell interface is augmented with a new material model. This quantity of raw data would normally be difficult and tedious to interpret without the data sorting and graphical representation traditionally referred to as postprocessing. How to model stresses and strains in comsol multiphysics. Oct 29, 20 principal stresses create another plot to display the principal stresses in the bracket. It can be observed that the stress variation with load is similar as in figure for each mesh size, but it can be seen the stress first decreases and then begins to increase as the mesh becomes coraser. To try this example yourself, see the wind turbine composite blade model.
Heres what you can expect after downloading version 5. Figure 14 shows the surface plot for load vs mesh size vs maximum principal stress. The combined basquin and coffinmanson criterion relates the strain amplitude to the fatigue life in both lowcycle and highcycle fatigue. The ray optics module is not like any other simulation software available for modeling ray optics, says dan smith, comsol software developer. How to calculate principal stress tensor in x and y direction on comsol. How to cite the principal stress and the principal direction. As a first step, the simulation of an unsteady viscoelastic flow inside a slot. This issue of multiphysics simulation, sponsored by comsol, inc. I defined cm as a variable in my pde but i want to force my equation first one in pic. In the process of hydraulic transportation of the piped carriage, the study of the stress of the water flow act on the cylinder wall of the piped carriage can help to improve the design of the piped. Comsol webinar modeling thermal stresses with comsol. The latest comsol software version brings you 20 demo apps and many new features and functionality updates to numerous products. Studying how your product behaves under a mechanical load is one of the most critical steps in the design process.
Comsol requires that every type of simulation included in the package has the ability to be combined with any other. Wall stresses in cylinder of stationary piped carriage using. For the most part, the discussion was confined to twodimensional states of stress. Implementation of a viscoelastic model to generate a shear stress. How to cite the principal stress and the principal. Sep 23, 2009 i have used the 2d plane strain mode to obtain the eigen frequencies of the radial and torsional modes of a circular 2d geometry. First, there exists an angle q p where the shear strain e xy vanishes. Today marks the release of comsol multiphysics version 5. Analyze layered composite materials with software from comsol. Implementation of a viscoelastic model to generate a shear stress test using the. Using just a few control variables, you can quickly come. The maximum principal stress of the chlorite is the smallest, indicating that the chlorite experiences the most damage under microwave irradiation, followed by the quartz. Using a representative 304l308l weld plate as a model in comsol, predicted residual stress shows some agreement with expected trends. There will be some repetition of the earlier analyses.
Comsol multiphysics has wide range of functionalities. The benchmark models in this book make up a subset of the test cases that are part of a continuous automatic testing. Here, the fully three dimensional stress state is examined. The benchmark models in this book make up a subset of the test cases that are part of a continuous automatic testing program. Ptt rheological models were implemented in comsol multiphysics and. Principal stresses and strains continuum mechanics. The solution i got is two times the analytical solution i have calculated. She joined comsol ab in sweden in 1992 and became the first sales representative for all scandinavian customers before moving to the burlington office in 2000. Comsol software verification and quality assurance programs comsol uses extensive manual and automatic testing to validate and verify the code. Introduction to structural mechanics module techylib. In earlier versions of the comsol software, only a single predefined stress or strain field could be selected, but now you can manually enter orientation vectors and corresponding principal values. Given the stresses at a space point in the body, s x, s y, and t xy, this calculator computes the stresses of the same space point in a rotated coordinate system, s x, s y, and t xy. Stress and equations of motion comsol multiphysics.
Pejman 2015 used comsol multiphysics software to perform threedimensional 3d simulations of thermomechanical properties of rock samples under microwave irradiation. Does anyone know the difference of first, second, and third principal stress. Fullycoupled simulations of thermallyinduced cracking in. Shall i use solid mechanics or shell for my study, my wellbore shows high strain even at low pressure. In substance for one point there is a plane where the shear stress is zero.
Calculator for applying plane stress coordinate transforms. For example, the default name of the plane stress application mode is smps. If you are designing a power supply unit, first check out the article on wireless power transfer from witricityno. In order to apply principal stress i created a 3d model.
The normal strains e x and e y and the shear strain e xy vary smoothly with respect to the rotation angle q, in accordance with the transformation equations given above. In a bar with a cross section a loaded by an axial force f, the stress in the direction of the force is. The symbol column lists the symbol notation for each variable. Is there a way to obatin the same results through the 2d axial symmetry stress strain mode. Interpret results of stress analysis inventor autodesk. Modeling stresses and strains in comsol multiphysics. Find out more about the dedicated functionality for modeling composite structures in the composite materials module. First and second pricipal stresses are similiar in both models. In the results tab, click the 3d plot group button, and add a contour plot. In a comsol multiphysics model, the variable names get an underscore plus the application mode name appended to the names listed in the tables. These variables are not visible in equation view since they are not computed by an explicit. In this stepbystep instructional video, you will learn how the solid mechanics interface in comsol multiphysics can help you solve structural mechanics problems through simulation. In comsol multiphysics software, you can directly combine all these effects by selecting joule heating and thermal expansion in the list of available structural mechanics physics interfaces.
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