MCADCafe Weekly Review March 24th, 2018

SOLIDWORKS: Continuity and Curvature Part II
March 24, 2018  by Rony Godoy

In Part I of this series, we looked at how the smoothness of curves can be analyzed and controlled. Now we’ll be taking a look at some additional analyses tools to further evaluate our surfaces as well as ways to improve our curvature continuous connections.

The zebra stripes tool (view>display>zebra stripes) allows us to see small changes on a surface that may be hard to see with a standard display. This tool mimics the reflection of long stripes of light on a very shiny surface. With zebra stripes, we can verify that two adjacent faces are in contact, are tangent, or have continuous curvature. As can be seen in the image below, the zebra stripes for contact do not have the same direction or size. The zebra stripes for tangent have the same direction, but change sizes where the tangency occurs – there are two points of tangency. And the curvature continuous stripes share the same direction and the same size throughout the entire surface.

Zebra stripes tool

We can even use our curvature display tool to further analyze our surface. The curvature display tool (view>display>curvature) displays the local radius of curvature in different colors based off of the curvature value. Surfaces with the least amount of curvature are displayed in black and the colors change through blue, green, and red as the curvature values increase (red indicating surfaces with the most curvature).

Curvature display tool

There are different ways to optimize curvature continuous connections between splines. One way is by using the equal curvature sketch relationship. This matches the radius of curvature and the direction between two splines, ultimately creating a smoother transition between the two entities.

No equal curvature Equal curvature

Another way to create a smoother transition between entities is by using the curvature control tool (right click a spline>add curvature control). The curvature control tool allows us to control the radius of curvature at a certain point on our spline. More importantly, it allows us to select an additional option which enables us to have a smoother transition between the entities. This option is called raised degree and is available in the property manager of the curvature control tool after it is placed on the spline. By selecting the raised degree option, SOLIDWORKS mathematically makes the spline smoother by adding additional control points. This option is automatically applied to splines that have equal curvature relations on both ends of the spline. As seen in the image below, the curvature combs have a smoother transition when the raised degree option is enabled versus not.

Curvature control Curvature control raised degree

By utilizing all of these tools we can ensure that our surfaces will be as smooth as possible. If you want additional information on splines, specifically style splines, read the following articles: The Style Spline in SOLIDWORKS – Part 1The Style Spline in SOLIDWORKS – Part 2The Style Spline in SOLIDWORKS – Part 3.

For more information, request a SOLIDWORKS 3D CAD quote or contact us at Hawk Ridge Systems today. Thanks for reading!

This week, PTC announced Creo 5.0, the latest release of its Creo CAD software that covers concept to manufacturing in a single design environment. According to the company, Creo 5.0 introduces five new and enhanced capabilities for  product design and productivity enhancements in the areas of topology optimization, additive and subtractive manufacturing, computational fluid dynamics, and CAM.

“PTC is on the leading edge of some of the hottest technologies today with the Internet of Things (IoT) and augmented reality (AR), but it has not forgotten its roots in CAD, instead transforming this business by infusing its leading Creo software with new technologies and capabilities,” said John Mackrell, chairman, CIMdata.

Topology Optimization

The physical design of products is often limited by existing designs and practices. The new Creo Topology Optimization Extension automatically creates optimized designs based on a defined set of objectives and constraints, and freed of existing designs and thought processes. This helps users save time and accelerate development by enabling creation of optimized parts for given tasks they must perform.

Creo automatically creates optimized geometric forms/shapes based on input conditions and defined criteria.

The Creo Topology Optimization Extension will be available Summer 2018 in the first maintenance build of Creo 5.0.

SOLIDWORKS Flow Simulation: Solving the Bucket Challenge
March 20, 2018  by Dayne McGuire-Lavallee Dayne

Which bucket will fill up first?

For all the SOLIDWORKS designers and engineering enthusiast out there, I’m sure you have seen something like this come across your social feeds at one time or another cause I know I have. The question is which bucket will fill up first if water is poured continuously into the first bucket. I have spent some time in the comments sections of these puzzles and been baffled by some people’s logic and responses. Most of the time there is a trick like a closed drain or hole in a bucket but some people were so confident in their wrong answer that I started to doubt my own intuition. So I decided to make a puzzle of my own and verify my intuition with SOLIDWORKS Flow Simulation. The modeling was very easy with some revolves and thin extrudes and below is what I came up with. If you were at any of our rollout events this should look familiar.

Bucket Puzzle

I modified the problem statement a bit with some assumptions so everyone can understand the intent of the problem and to potentially combat any over-analyzed responses.

Water will be poured into bucket 1 at a slow enough flow rate that it will drain before it begins to fill. The system is open at the ends so there will be no buildup of air. Which bucket will fill first?

I had to modify the problem statement for a couple of reasons because if I dumped the ocean into the problem bucket 1 would fill first so we are assuming the flow rate is ideal for the buckets drain faster than they fill. This cross-sectional view shows lids on the buckets and those are only there to help define the boundaries in the flow simulation but are considered pipe openings so there will be no air buildup. I challenge you to examine this puzzle and determine which bucket will fill first. Before I give you the answer I am going to talk about the free surface flow simulation that I used to solve this puzzle.

Free surface lets you simulate flows with a freely moving interface between two immiscible fluids. It’s like water flowing in an open channel or a half full pipe. It uses the volume of fluid method for tracking and locating the free surface interface of gas-liquid or liquid-liquid pairs. Any phase change, rotation, porous media, or fans are not allowed. For more information and an additional example of free surface flow inside of SOLIDWORKS flow simulation check out this BLOG.

So now I present the solution brought to you by SOLIDWORKS Flow Simulation. I am happy to say that the simulation went just as I planned, giving me a lot of confidence in my own intuition and the capabilities of SOLIDWORKS flow simulation.

For more information, check out our website to get a SOLIDWORKS Flow Simulation Quote or contact us at Hawk Ridge Systems today. Thanks for reading!


Kenesto: 30 day trial

You are registered as: [].

CafeNews is a service for MCAD professionals. respects your online time and Internet privacy. Edit or Change my newsletter's profile details. Unsubscribe me from this newsletter.

Copyright © 2018, Internet Business Systems, Inc. — 25 North 14th Steet, Suite 710 San Jose, CA 95112 — +1 (408) 882-6554 — All rights reserved.