Hello everyone! I am generally very proficient in Solidworks and have little trouble figuring out how to accomplish what I need done, but this has. COSMOSWorks Professional. Finite Element Analysis with COSMOSWorks Paul M. Kurowski Ph.D., SDC. Schroff Development Corporation. SDC Publications: Online Resources for Engineering Analysis with COSMOSWorks ().
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Or, what happensto the structure of a storage tank if the crane putting it in place should dropit? Until now, determining the results of such accidents required running physicaltests that destroyed the structures under study, or else performing very cosmosworrks and dynamic response FEA finite element analysis better suited tosimulating car crashes.
COSMOSWorks now makes it possible for design engineers to run upfront droptests on their designs easily and quickly, despite the fact that running theminvolves studying tens of thousands of very short time steps to capture the resultswithin microseconds of the impact.
This article examines what a design engineerneeds cosmoswworks do to perform such a test, what kind of results he or she will obtain,and explores the technology behind such simulations.
For the user, running drop tests looks and feels just like doing any other COSMOSWorksanalysis; setting up a drop test is just like setting up any other study. Specify Drop Height and Floor Orientation.
In setting up the study, you choose either to specify the drop height that is,the distance to impact or velocity at impact, which can be defined by a motionstudy conducted prior to the drop test. If you choose a height study, ccosmosworks thendefine whether to measure from the centroid or center of the object or fromthe bottom of the object.
The default angle of theflooror other surface onto which the object drops is cosmosworkx to gravity. However, youcan change that angle and, if desired, enter cosmosworkx about any friction the fallingobject would experience when hitting the floor. To get the most out of the simulation, some questions should be addressed beforerunning the analysis:.
Solution time after impact is measured in microseconds. The total duration dependson how much time elapses before the object experiences all the likely impact stressit will undergo after it bounces. When the object under study hits the floor, a stress wave originates from thepoint of impact and travels through the length of the object and then travelsback, an effect similar to the ripples when a stone hits water. In illustration, think of a toy airplane crashing nose first onto the floor. The stress wave generates from cosmoworks nose of the plane hitting the floor and thentravels towards the wings and the tail.
CosmosWorks Shaft Analysis
Figures 3 through 6 illustrate this stresswave progression. The simulation needs to be run for a considerably longer time to study secondaryimpacts.
An easily visualized example is the toy car shown here, which drops sothat the rear wheels hit the floor first, and then are followed by the front wheels,causing an initial and secondary impact. Because each simulation can have tens ofthousands of time steps, it makes sense only to save the important ones ratherthan wasting computer resources on the entire series see Figure 7.
You may be able to cut more time from analysis runs by performing a first passrun, using default settings, to obtain initial results.
As illustrated in the propane tank shown in Figures 9 and 10, running a droptest in COSMOSWorks makes it easy to study the impact on objects dropped in differentorientations. Containers that carry hazardous materials, for example, have differentdesign requirements to account for being dropped in different orientations.
COSMOSWorks drop test simulations also support plasticity, so that design engineerscan determine such permanent deformations as dents after impact. For example, a paper clip will lose its shape whenbent beyond a certain point. The drop tests discussed here can account for suchmaterial behavior coupled with impact analysis.
The initial release of drop test capabilities in COSMOSWorks does not supportinteractions or contact between components within an assembly after impact, orimpact between two objects. In addition, these simulations assume that the flooror other impact surface is infinitely stiff compared with the dropped object.
Although experienced COSMOSWorks users will find the steps involved in runningdrop tests familiar, the technology behind them is more complex than it looks. FEA can use two approaches for solving this equation: Althoughboth approaches are equally accurate, implicit solutions of impact problems suchas dynamic drop tests take longer to solve. On the other hand,explicit techniques have the drawback of requiring very small time incrementsto provide a good, stable solution.
Real-life problems generally can be solved using either approach, but dependingon the nature of the problem, one method will be faster than the other.
Linearproblems that have slowly varying loads with no cosmisworks component are more cost-effectiveor faster to solve with implicit methods. Problems with gross nonlinear behavior that requires a constant updateto the stiffness matrix are also more economical to solve with explicit methods.
The speed gained through technology and through ease of use makes it simple forusers to run drop tests on their cosmoswirks, and adds a welcome dimension to overallupfront simulation.
Complex nonlinear analysis technology underlies ease of use. Discrete element method simulation software cosmoaworks particle collision analysis, spring and damper motion, fiber modeling The RX portfolio focuses on applicability, efficiency and scalability.
Development of an integrated tool able to optimize the geometric features of a door trim Designing occupant friendly interiors that meet requirements in both safety and style, necessitates the extensive When 20005 specify a drop height, the program automatically calculatesthe velocity just before impact. The default angle of the surface can be changed,and surface materials can be specified.
Figures 3 – 6: Run Analysis and Study Results To get the most out of the simulation, some questions should be addressed beforerunning the analysis: For how long after impact should one observe or capture the solution?
Because each simulation can have tens of thousands of time steps, itmakes sense only to save the important ones. You can cut more time from analysis runs by performing a first pass. Those results may indicate time windows that need to be refined and you can choosethe ones to refine. How do you select the time steps to save from your results? Figures 9 and Csmosworks is especially helpfulwhen designing containers that carry hazardous materials, such as these propanetanks.
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