Refer to the help page for CONTA175, for a detailed description of the real constants for this element. As in the previous case, we'll use the default values set by ANSYS for our analysis. Click on Add, select CONTA175 and click OK.Īs you can see, ANSYS uses several real constants to control contact behavior. Now, let's look at the real constants for CONTA175. We'll use the default values for our analysis. ANSYS will default R1 and R2 to zero once the target elements are generated. For contact problems, it is recommended to first try using the default settings, and then change them if difficulties are encountered or the analysis has special situations. Real constants R1 and R2 define the geometry of the target elements. Now, let's look at the real constants for TARGE170. Take a look at the help pages for SOLID92, under SOLID92 Input Summary, and you will find that there are no real constants to be specified for this element. You should get a note "The SOLID92 element type does not require real constants". This brings up the Element Type for Real Constants menu with a list of the element types defined in the previous step. Main Menu > Preprocessor> Real Constants > Add/Edit/Delete > Add Select Contact in the left field and pt-to-surf 175 in the right field. This brings up the Library of Element Types menu, select Contact in the left field and 3-D target 170 in the right field. Main Menu > Preprocessor> Element Type > Add/Edit/Delete > Add. Since TARGE169 elements support 2-D analysis and TARGE170 support 3-D analysis, we will use TARGE170 elements to mesh the target surface. This element also supports 3-D structural contact analysis, as shown in the Contact Capabilities table (10.1), and we'll use it to mesh the contact surface.įor the target surface, we can use either TARGE169 or TARGE170 elements. If you read the ANSYS Contact Capabilities help page, you will find that CONTA175is one of the node-to-surface contact elements that can be used to represent contact between a node and a surface or between two surfaces. However, we expect the surfaces of the disks to come into contact once the force is applied. Table 10.1 summarizes the different elements available.įor our problem, the initial interaction between the disks is at a point. Each type of model uses a different set of contact elements. Note that ANSYS supports three types of contact models: node-to-node, node-to-surface, and surface-to surface. Click on ANSYS Contact Capabilities which is the third topic from the top. This brings up the Chapter 10 Contact help page. Double-click on Contact analysis which should be the first topic listed. Select the Index tab and type in contact analysis as the keyword. Let's take a look at the different elements available.
Think of the contact elements as the skin of the surface that is expected to come into contact. The contact elements will overlay the solid elements ( SOLID92) and will describe the boundary of the upper disk (contact surface) that is expected to come into contact with the lower disk (target surface). Once the contact and target surfaces are identified, the next step is to select the contact and target elements. As a result, the curved surface of the upper disk will be the contact surface. We will define the curved surface of the lower disk to be the target surface (larger of the two). These are the curved areas that are initially in contact at the point of contact. If one surface is larger than the other surface, the larger surface should be the target surface.įor our problem, there are two surfaces that are expected to come into contact. There are various guidelines for defining contact and target surfaces. In contact problems, one needs to identify the surfaces that are expected to come into contact, and group them into either "contact" surfaces or "target" surfaces.