Dimensions Window

Click on the thumbnail for larger image

The dimensions tab is used to enter information about the tube, composite and steel dimensions, stacking sequence and if necessary ply by ply tension. The important aspect pertaining to this section is the analysis type button which specifies whether a single point analysis is carried out or the profiler is used to design the entire barrel. See below to find out information about this tab.

No. of plies: This value corresponds to the number of plies on the tube surface, and is not considered an input for the following reason. For design purposes the number of plies is considered as a whole integer value corresponding to the composite thickness divided by ply thickness. This is done for a few reasons:

• The numbers will match up, i.e. the composite thickness will be a whole n number of plies thick. If the thickness is less than a whole integer of n plies then the number is rounded down.
• When using the profiler it is much easier to have the number of plies at each location determined by dividing the ply thickness by the composite thickness at that location. Winding applications typically involve the same single ply thickness by which the final thickness is n number of this thickness.
• If the user wishes to use different thicknesses for each layer, simply use the smallest thickness as the ply thickness, and introduce n times this thickness for the thicker layers. For example, if I had a two layer [0^o/90^o] composite, one thickness is 0.005" and the other is 0.015", simply put together a 4 layer system by setting the [0o] ply thickness to 0.005" with the remaining three layers completing the the [0o/90o] lamina. If the ply thicknesses are not divisible by n, then simply select a thickness that is divisible by both and use this as the layer thickness. Please note that this option may increase the number of plies considerably, especially if one ply is 0.037" and the other is 0.011" thick, but these thickness variations are not common in filament would structures.

Ply Width: This corresponds to the ply width (in inches) for filament wound structures. It's value is used to determine the effective stresses incurred when the structure is wound under tension.

Ply Thickness: This corresponds to the thickness of each ply and as mentioned earlier is used to determine the number of plies when a composite thickness is specified.

Bore Radius:  This is the internal diameter of the tube bore (in inches).

Analysis: This button is of the most important options in the CCDS application. This option is used to specify if a quick single point analysis is carried out or whether the profiler is used. Be sure to know at all times what this option is set to as your entire analysis is governed by this option. You'll notice that throughout the program, certain options will be enables and disabled depending on which mode you are working in. For instance, the profiler uses a pressure gradient along the length of the tube, so the option to input a pressure value is disabled in the process/load tab. You can override this specific option, which is explained in the process/load section, but generally speaking your options throughout the program will change depending on which mode you select.

Thickness: This is the first option you'll see change when deciding on which analysis you choose. When Profile mode is selected, the composite and bore thicknesses are highlighted which indicates what thickness is being used at a particular location on the barrel. In single point mode, the user inputs for bore and composite is highlighted and the user can input the desired composite and steel thickness.

Layer Info: This is where the user inputs the material I.D. (which is designated in the materials input tab), the ply orientation (in degrees, with 0o representing the global axial direction, and 90o being the hoop direction), and the ply by ply tension (in lb) if needed. (If a common tension is used it can be entered in the process/load window, this saves time in having to enter the same value for each ply). The user can load and save this information using the load and save button. The file suffix by default is *.lay.

Layer Summary: This plot simply shows the ply material ID, orientation and winding tension in a graphical format. It can be used t quickly see problems with laminate stacking sequence or material ID specifications for large stacking sequences.