Computer Aided Design Process and the American Automobile Industry

by RW (Bob) Sheaves, CEO, catNET Incorporated

My business (https://www.catnetsolutions.com) performs business process planning for the automotive industry, as a whole. Because of our associations, I see a lot of people in this industry, in general, concentrating on tools and their price, and NOT concentrating on the job at hand- meaning “What are you going to DO with these tools?”

In a real example, a particular customer asked us to provide an evaluation of various CAD packages based on cost. (We do not sell any software or hardware, but provide planning, setup, integration, support, and training.) This customer was looking solely at price, not how his company used the tools:

MAKING DRAWINGS:

The first question needed to be asked was simple-”How are you using the information from the engineer’s mind?” Paper drawings are a proven waste of time, effort and resources in any manufacturing business. For example, look at a single cast lower control arm, such as used in the Dodge Durango in the MY2000 vehicles (as well at its stablemate, the Dodge Dakota).

http://www.consumeraffairs.com/automotive/dodge_dur_steer.html directly addresses customer complaints on this vehicles steering and suspension. No verification of individual claims has been made by this writer.

This control arm has no moving parts, in and of itself, and incorporates a compression style ball joint (this balljoint design was found to be faulty by NHTSA investigators and subject to recall.) at the wheel end, with 2 rubber isolators providing geometric rotation around a common axis to allow jounce and rebound travel. Made from cast ductile iron, this part only contains 5 machined areas:

1. Forward bushing bore and spot faced length control
2. Rearward bushing bore and spot faced length control
3. Ball joint mounting surface (for mechanical hot riveting)
4. Sway bar end link mounting surface
5. Sway bar end link threaded hole

To completely design this part and detail all the necessary forms and shapes needed for tooling and fixturing, took a total of 59 drawings of multiple views and GD&T (Geometric Dimensioning and Tolerancing). The time expended on this was a total of approximately 500 man hours of labor, including the checking of the drawings for completeness, fit, and function. This time does NOT include the separate engineering procedures needed to ensure a quality part that performs to design and program intent. The cost, at an industry average wage, including overhead, of $75 per hour means that $37,500 was spent on a design that was destined to failure and cost the company millions in recall costs.

A modern 3 dimensional modeling tool, such as CATIA or BRL-CAD, generates a part in that same manner as you would manufacture it, the model has mass, dynamic properties, and tooling information, all bound into the definition of the part, subsystem, or assembly. There is simply no reason to make drawings as the cost of that paper will ALWAYS outweigh the costs of going from model, with simultaneous FEA analysis, simultaneous dynamic analysis, and manufacturability analysis, to manufactured part, when all the costs are added (Root Cause Method.

PARTS DEFINITION:

A “part” can be defined as a piece of material, manufactured to provide functionality of some sort. This part has a mass (or “weight” in common terms), a moment of inertia (dynamic properties when it moves in its function), material properties (what it is made from and how it forms in various manufacturing methods), thermal characteristics (heat transfer), and other esoteric properties the average person does not care about, but is of prime interest to various engineers, based on the use of the part.

Accurate modeling of all these parameters are necessary if you are to make efficient reuse of all the information in the overall business process. Dr. Deming teaches us that “re-” anything is a loss of efficiency…re-work, re-pair, re-build, etc. To be able to capture all this specified information is paramount for the initial choice of a CAD/CAM system. The model represents what is called “Design Intent” and is the “stake in the ground” against which all SPC, GD&T (or FD&T if you wish), and other processes utilized in manufacturing are measured.

Without the most accurate model possible, you fall subject to the “law of unintended consequences” and end up, in an extreme instance, of killing people because you just didn’t know something.

Boeing is very aware of this fact, IBM the same, DCX the same, Ford the same, etc…..

What is the common denominator among the companies listed? CATIA or Computer Assisted Three dimensional Interactive Application. In CATIA v4 or v5 (unix or PC based) you have a single location of a part in the process, which all information is centered around, through ENOVIA (functionally, a relational database, when combined with it’s component pieces making a PLM system) enabling all parts to only be designed one time, and most importantly, in one place. This alone was worth (in 1989 dollars) over $2.5 million to a particular automotive company in saved revenues. This also allowed a reduction of time, indirectly, as CATIA allowed only 1 version of a design to be used - all could see the part in the virtual space the vehicle is built in, but only ONE could modify that assigned part. All those using that particular part in their “space claim” were immediately updated with the latest changed. By using solid modeling technology, this company was also able to automatically check for assembly, function, and fit without human intervention and “pissing contests”. If the part did not fit or function within the assembly, it was flagged for reprocessing, along with the interfering ancillary components.

IS THE PART MADE CORRECTLY OR NOT?

Data translations between systems, through either direct translators, or intermediate file format conversions (such as IGES and STEP 203/213) are fought with alligators in the path of the unwary. Class “A” surface definition is lost during translations, competing CAD programs do not utilize the same math in computing elements of the designs (Bezier curves vs. NURBS ), system accuracy is not the same between the systems (19 digit accuracy, versus 7 digit accuracy), etc. 19 place accuracy sounds like it is meaningless, since for all practical purposes, you are defining a length less than the difference between colors in the light wave spectrum.

This simplistic approach has one VERY fatal error built into it….that is, the purpose of the design intent - a STAKE IN THE GROUND - does NOT exist.

If the “stake” is constantly moving, there is no way to determine what is correct , except by judgment A very poor and expensive learning process, as Chrysler found out.

This means the CAD system MUST integrate directly between and “outside” analysis programs (such as ADAMS and DADS for dynamics analysis, NASTRAN for FEA, LS-DYNA for crash simulation, etc.) Failure to accommodate this interoperability brands such companies as “poseurs” and will not be taken seriously by those that will control the funding for research and manufacture.

WHAT ALL THIS MEANS?

In summation, it is my opinion that the choice of a CAD system is way too early at this time, since the parameters of the basic design have neither been decided nor published on record here. Choosing what are the important parts of the design, how it is to function, and what the general approach to take is FAR more important to the success to the project, at this point in time. Also, the fact that such a closed source system as CATIA exists, is NOT a recommendation, but rather, by concentrating on setting the design operational parameters, an intelligent choice may be made by comparing OPEN SOURCE software, such as BRL-CAD, to the CLOSED SOURCE software, such as CATIA.

Best regards,

Bob Sheaves
CEO
catNET Incorporated

What will be powering our cars in the future?

I think that we can all agree that one day in the future, the world’s supply of oil will run out. We may however disagree on the actual day the oil runs dry. Some experts believe that this may happen in a couple of years from while others believe there is enough oil in the ground to supply the world’s needs for generations. Either way, oil is not a resource that is either renewable nor replenish-able.

I will give two pseudo-concrete reasons for the depletion of oil.

Saudi Arabia (one of the world’s largest suppliers of oil) has not made a major discovery of an oil field in at least a couple of decades. In order to keep the pressure of their current oil fields in check, the Saudis have resorted to pumping water into their oil fields (a common tool for depleted fields) and the rate of pumped water has skyrocketed over the last couple of years. However, they also admit that they have previously underestimated the amount of oil in each of their fields and have, year after year, increased their oil reserves. Their actual numbers and techniques for this may not be up to par with what the West may consider truly accurate and therefore we must take these numbers with a grain of salt.

Second, there is this famous gaussian curve or bell curve that was able to predict the decline in reserves in Texas. The author of this paper stated that there exists a second bell curve that relates production of oil from the wells. These two curves, one for the discovery of wells and the production from wells are separated by a couple of years. He was able to predict the exact year when oil production in Texas would begin to decline. This technique has been recently used on the world’s supply of oil and has been predicted that around 2010 that supply of oil would begin to drop.

So what will be the world’s next source of energy. Solar, wind, nuclear (fission), fusion, coal, etc.

One tool could be the use of coal. There is more coal in the state of Pennsylvania then oil in the Middle East. Nazi Germany constructed a way to make gasoline from coal. This technique is still in the early stages but is beginning to ramp up. Colorado is another state that has a lot of coal and is closely watching the research that is going on in Pennsylvania to see if it is profitable for them to invest in this “new” technology.

Solar power at this moment is an inefficient way of gathering energy. It takes more energy to produce the solar power cells than the cells themselves bring in. However, in the last decade new technologies have increased the efficiency of the cells for them to become more productive. Same goes for wind driven windmills. Lighter, more efficient materials are being created for windmills, which have driven up their efficiency.

Nuclear energy is extremely efficent, but the byproducts of the Uranium has very long lifetimes. These byproducts go through alpha decay (releasing helium atoms), beta decay (releasing electrons), and gamma-decay (releasing gamma-rays). These byproducts of the byproducts can cause cancer is exposed for a long enough time. And it is not just the byproducts of Uranium that is dangerous, disposal of the reactor core is a huge problem because it is extremely radioactive.

The only and real saviour will be cold fusion. I love just saying those words. So fusion is when you take two atoms and collide them together to form another atom. This is what fuels our sun. To make a long story short, the sun takes 4 hydrogen atoms to make 1 helium atom plus energy. Humans have been doing the same for years in particle accelerators FermiLab in Chicago and CERN in Switzerland to name a couple.

The problem is that we need to put so much energy into the process to get very little energy out (electromagnets etc). Hence the name “cold” part in cold fusion. Think of spider-man 2 if you will. How do we control the reaction without putting as much energy into the system while efficiently taking the heat out of the system?

Now I will go back to the original topic of the blog…What will be powering out cars in the future? The answer my friend is hydrogen.

The hydrogen in water or H2O is a chemical bond formed by the attraction between the electronegative region of an oxygen molecule and the electropositive region of a proton that is bonded to an oxygen. It is weaker than a covalent bond, having a binding energy of about 2-10 kcal/mol. So in order for us to power our cars with hydrogen we must put energy into breaking hydrogen from water.

Mixtures of hydrogen gas and air do not react unless ignited with a flame or spark, in which case the result is a fire or explosion with a characteristic reddish flame whose only products are water. 2H2 + O2 leads to 2H2O

So hydrogen isn’t the holy grail that we all think about. Oil is running out…don’t worry we will use hydrogen to power our cars. The problem is we get as much energy out as we put into the system. The holy grails are the forms of energy that we release the hydrogen from the water. It is the gasoline from coal that we may use or nuclear or fusion type reactors that will eventually “save” man-kind from a second dark ages.

Now what did I do?

Now what did I do????

There has been a great upheaval in the automotive industry over the past 20 years. More change, at a faster pace, affecting more and more people, all has conspired to create a general apathy in the motoring public towards their second biggest investment after the home, as change far outpaced the desire to understand and anticipate this change. Change in suppliers, change in techniques, change in processes, change in attitudes and even change in direction, all have conspired to bewilder many that could have developed an enthusiasm for cars. Dr. Zatz and I discussed at length, all of these issues, over the past couple of years and how they have impacted, both positively and negatively, the general American driving public.

This notebook of thoughts and explanations (I dislike the term “blog” for reasons best left unstated) will, in the coming months, provide an understandinng to today’s enthusiast, the reasoning behind the direction of the development of automobiles. Over time, I hope my explainations of how cars, trucks, and other transportation devices, from an engineering and business standpoint, will be of help to you all in aiding your understanding.

I will not be offering my personal views, but instead, concentrating on the “numbers”, such as explaining how and why some “less than thought out” ideas that may make sense to the layman, simply are either flawed, or a positive advancement. Personal opinions will NOT enter into these explainations. Specific subjects to be talked about will be fuel comsumption (how it is calculated), fuel types (why a particular fuel is good or bad), how performance is predicted and tested (I’ll throw out one of the terms now…”gradability”), and other sundry things.

May God have mercy on my soul…..

Commentary

At the end of each article, I will generally include observations and opinions specifically related to the article in a seperate “box” labled “Commentary” to provide visual seperation between fact and my imagination. If you wish to see specific topics covered, please feel free to email me at rwsheaves[at]catnetsolutions.com . I may not answer directly, but I will read all your comments and adjust the explainations as needed. This is not about me, as some may suggest, but it is about YOU!

One final note-this will not be more regular than monthly, usually, due to the time my work schedule allows.

Best regards to you all……

Bob