Now that ANSYS 15.0 is released the next thing many of you will be doing is downloading and installing the new version.
NOTE: This blog is aimed at current customers. If you’re not a current customer you might want to tune out now and watch for tomorrows blog!
We’re providing several materials to help you to successfully get through this process so you can get on with using the new functionality in ANSYS 15.0!
When you go to the customer portal to download the software you will notice that you are taken to a Getting Started page. This page contains the information you should need to install the products successfully. We recommend that you pay special attention to the installation section which contains video’s and documentation links that can guide you through the process. 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
I recently wrote a blog that outlined a formula to scale a multilayer stack actuator under axial deformation (stroke). In that blog we found out that “(n = number of layers)” was the multiplying factor that made this scaling valid. Yet another question came whether it we should also multiply by “n” if we are to model multilayer bender actuators using a bimorph or a unimorph!
Let’s start by first explaining what are unimorph and bimorph devices?
Unimorph and bimorph devices are characterized by the number of piezoelectric ceramic plates. One ceramic plate bonded onto an elastic shim would create a unimorph, whereas two ceramic plates bonded together would form a bimorph device. In this blog, I will focus the discussion on bimorph devises.
As shown in the figure below, a bimorph device is composed of two ceramic layers with opposing polarization direction, when an electric field “E” is applied, one layer produces an extension, while the other layer contracts causing the cantilever bimorph to bend. Continue reading
In my last blog, I presented some fatigue background information and introduced why CAE can be a powerful tool for assessing fatigue damage. In this blog I will provide an overview of the ANSYS fatigue capabilities, particularly the powerful ANSYS nCode DesignLife product.
Let’s start with the original set of ANSYS fatigue capabilities. Many, many years ago, the capability to perform fatigue calculations in accordance with Section VIII, Division 2 of the ASME Boiler and Pressure Vessel Code was introduced into “classic ANSYS” — The current version of that product is known as Mechanical APDL or MAPDL. The commands used to perform this type of fatigue assessment (FS, FSNODE, FSSECT, FTCALC, etc.) are now collectively referred to as the “MAPDL fatigue module”. These commands are not a separate software product. They do not require a separate license. They are included in MAPDL and can be accessed with a Professional license and above. The MAPDL fatigue module is not a general purpose fatigue tool. It does ASME B&PV Code fatigue calculations, nothing else.
Later ANSYS developed a general purpose, entry level fatigue tool that was accessible from inside ANSYS Mechanical on the Workbench platform. It supported Constant Amplitude, Time Series, and Time Step loading (2 load cases only) for Stress-Life fatigue and Constant Amplitude loading for Strain-Life fatigue (Note: I will discuss loading mapping in more detail in forthcoming blogs.). This product was referred to by several names; Workbench fatigue tool, Workbench fatigue module, Mechanical fatigue tool, fatigue add-on, etc. It was offered as a separate product that required an add-on license. The MAPDL fatigue module and the Workbench fatigue tool are completely unrelated. They are both are mature features that are no longer actively being enhanced. Continue reading
The key to a balanced life is clean living. There are some simple rules to live by. Always tell the truth, even if it makes you look bad. Don’t spend more than 10 dollars for every 10 dollars that you make. Never steal another man’s wife, his horse, ox or his cattle prod. And never try to push on a rope. If you keep to these simple rules, your life will remain in balance.
As it is in life, so it can sometimes be in the FEA world. There are some first principle rules to live by to keep things in balance.
For example, if you apply a torsional load via remote points, don’t expect your reactions to always balance if you run this as small deflection. Remote loads and displacements in Workbench Mechanical are implemented using constraint equations. With small deflection analysis, we do one pass thru the linear code. These constraint equations are only created once. If the resulting rotation is large enough, the CEs might become invalid thru the large rotation. In the end, things will not add up. We do issue a warning in the solver output. If in doubt, always turn large deflection ON before checking anything else. 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
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