A threaded bolt connection is used to hold two or more parts together to form an assembly of a mechanical structure. In order to achieve expected physical behaviors of a threaded bolt connection, a detailed three-dimensional bolt model, which fully includes the effect of the true thread geometry and the frictional behavior at contact interfaces is sometimes desirable. In such a case, geometrically modeling the thread will lead to a high number of elements in order to accurately capture stresses, also meaning unaccepted computational cost.
ANSYS Mechanical 15.0 introduces a new bolt thread modeling technique via the contact elements, which eliminates the need for a detailed mesh discretization of the threads. The computation of the thread occurs by internally modifying the contact region to match the thread’s geometry. This feature offers simplified modeling with the near accuracy of a true threaded-bolt model. The computation time for getting stresses in the thread area is then reduced by a factor of 10 compared to the true threaded-bolt model. Continue reading
In my last blog, I highlighted that HBM nCode is the world-wide leading developer of CAE durability software. They develop HBM nCode DesignLife, which is the leading FE based fatigue analysis software product. I discussed how ANSYS, Inc and HBM nCode partnered to develop the ANSYS, Inc supported ANSYS nCode DesignLife product. Thus, two variations of DesignLife are now available to ANSYS customers — HBM nCode DesignLife and ANSYS nCode DesignLife. Both versions have identical core capabilities, so what’s the difference between ANSYS nCode DesignLife vs. HBM nCode DesignLife?
The answer is Workbench!
HBM nCode DesignLife is a standalone product that is a good solution for a wide range of CAE tools. ANSYS nCode DesignLife is data integrated into the Workbench environment enabling it to provide state-of-the-art CAE fatigue analysis capabilities along with the ease of use features of the Workbench environment. This integration highly optimizes the workflow for ANSYS users. Some of the benefits of this Workbench integration are: Continue reading
Tomorrow, December 6, is an important day for many because it’s the final draw that will deliver the verdict on the eight football (soccer) groups that will kick off the 2014 FIFA World Cup — one of the most popular sporting events in the world, surpassed only by the Olympic Games. The 2014 World Cup will take place in Brazil from June 12 to July 1. This year will be special for me because, for the first time since 2002, Belgium has qualified. The team from Belgium includes a large number of players from prestigious European championships, so we have a fair chance to go quite far in the competition.
Whether the Belgian team will be a tough competitor or an easy seed could influence the rest of the World Cup. Unfortunately, it is very unlikely I will be able to support our Belgian Red Devils in person in Brazil next summer. But I’ll feel a part of the event thanks to the remarkable work done under the auspices of NOVACAP, Maruska Holanda and Pedro Almeida performed by Prof. Paulo de Mattos Pimenta and ESSS, the ANSYS channel partner in South America.
The Stadium That Will Host the 2014 World Cup
The National Stadium of Brasilia Mane Garrincha
Because a stadium is usually considered a prestigious landmark that is expected to last for decades, the quality of the design is crucial. The stadium must be able to withstand any situation it might experience during its lifetime such as heavy wind or cheering crowds. Continue reading
There are three methods available for extracting the reaction forces across a contact region in WB-Mechanical:
- Contact(Underlying Element)
- Contact (Contact Element)
- Target (Underlying Element)
When you choose ‘Contact(Underlying Element)’, the code is selecting the contact elements associated with that region, selecting nodes attached to the selected contact, and then selecting elements attached to the selected nodes before calculating the reaction.
Below is an equivalent APDL command script, where “cid1″ is a parameterized contact element type number for the region of interest. Continue reading
An assembly line is a manufacturing process in which parts are added in a sequential manner to create a finished product much faster than with handcrafting-type methods. Can we apply the same principles to simulations?
Many a times, a new product is made by using components from some previous designs along with some new parts. So, when performing engineering simulations on the new design, is there an efficient way to leverage the unchanged components from the previous design?
In today’s distributed workforce, various components of a product may be designed at different locations; some even by external contractors. When analyzing the full product, is there a way to directly use the analysis models from the different groups? Continue reading
Sometime ago, I wrote an article entitled Best of Both Worlds: Combining APDL with ANSYS Workbench for Structural Simulations. When I read this article today, I think of three things:
- We have made a lot of progress in our latest releases so the use of MAPDL is reduced or irrelevant for the most common tasks we perform. With our added options, loads, or boundary conditions, models can easily be accessed by everyone without commands.
- The content of the paper is still relevant, as many of you have created and validated APDL scripts over the years that you can reuse “as is” in the Mechanical application.
- And last but not least, you can now give all of your scripts a Workbench flavor by integrating them in the Mechanical application through buttons, menus and new items in the simulation tree.
Piezoelectricity is the ability of certain crystalline materials to generate an electric charge proportional to a mechanical strain (direct piezoelectricity). Direct piezoelectricity was discovered by Pierre and Jacques Curie in 1880 when they were studying the effect of pressure on natural single crystal structures such as tourmaline, quartz, topaz, and Rochelle salt. Converse piezoelectricity is rather the ability to generate mechanical strain in response to an applied electric charge. Piezoelectric stack actuators are a good example of this converse effect. They are increasingly used in micro-positioning applications due to their precision and responsiveness.
Since ANSYS Workbench has been released, the question of whether piezoelectricity can be modeled in workbench has been very popular. Thanks to ‘command snippets’ that made it possible to use APDL commands to convert a certain part of your model to piezoelectric element (PLANE223, SOLID226, or SOLID227), and assign piezoelectric properties to it. Although this has been a fantastic feature, it was not really pleasant to non-APDL users. Continue reading
Many ANSYS commands that have the capability to operate on groups of entities have the ability to process the “selected” set of entities. For example, on the NGEN command the fields “NODE1,NODE2,NINC” can each have values or you can use NSEL commands (and many others) to select a set of nodes and then use ALL in the NODE1 field. The *VMASK command effectively adds the select capability to the *VGET, *VPUT, *VFUN, *VOPER, *VSCFUN, *MFUN, *MOPER, and a few other commands referred to as the
*Vxx/*Mxx operation commands. Here are a few important items to be aware of.
Conceptually speaking, when you select an entity, such as a node, the program sets the select flag for it to be 1 (true) and unselecting a node then sets the flag to be 0 (false). The select flag setting remains until another select command alters it. Arrays and tables store numerical values and have no “connection” to where they came from so the array contents do not know whether they are from a node’s x coordinate, an element’s I node number, or some load value. The *VMASK specification affects only the next *Vxx/*Mxx operation command. As soon as a *Vxx/*Mxx operation command is processed the *VMASK and all other array operation modifiers are reset. Continue reading