KIPS
KIPS
(OP)
I am drawing a blank in converting a KIP into a load specvified in Kn.
Can anyone supply a ratio or give me a clue0n how to convert
Can anyone supply a ratio or give me a clue0n how to convert
When was the last time you drove down the highway without seeing a commercial truck hauling goods?
Download nowINTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
|
RE: KIPS
RE: KIPS
1 kip = 1,000 lb-f = 4.448 kN
HTH
RE: KIPS
and, I thought that kip was the name given to Laos currency!!!
RE: KIPS
A Kip is a Kilo-pound.
A hip is a hecta-pound.
A mip is a millipound.
A dip is a decipound.
A cip is a centi-pound.
Have phun!
RE: KIPS
Here, some additional information:
1 pound (lb) = 453.59 grs, or 1 Kg = 2.205 lb
Kg = 9.80665 N = 2.205 lb, from where: 1 lb = 4.448 N
1000 lb = Kip = 4.448 N x 1000 = 4.448 kN
Kg/ cm2 = 14.223 psi
psi = 0.0703 Kg/ cm2 (this value is more exact)
N/m2= Pa ; and since: m2=(10)^6 mm2 ,(10)^6 Pa= MPa= N/mm2
MPa = 145 psi.
Now:
(f´c)^1/2, in psi= 1/145*(145 f´c)^1/2= 1/12(f´c)^1/2,MPa
Also:
(f´c)^1/2 , in psi = 1/14.22*(14.22 f´c)^1/2 = 0.265* (f´c)^1/2 , Kg/cm2
For example, vc = 2* (f´c)1/2 ,psi = 0.53* (f´c)1/2 , Kg/cm2 = 1/6 * (f´c)1/2 , MPa
Is this important ?. I think so, and for this reason I posted “Equivalence of units in ACI 318M-02” in the ACI Code Forum.
RE: KIPS
RE: KIPS
As far as the British using pounds vs. euros. I have no idea. Maybe they should all convert to talents. My air conditioner has a rating in Btu's and I haven't seen an Eu tu ("you too") air conditioner.
In all seriousness, I first heard the term "kip" in statics class many moons ago and was confused. During the evening's homework session, I looked it up (this was in the pre-web days) and made the "kilo-pound = kip" konnection. Whenever anyone asks me what a kip is (it happens a lot, really: I've had architects, ME's, EE's and even a couple of civil engineers not to mention the many laypeople ask) I tell 'em "it's a kilo-pound, get it? KIlo-Pound." That's the best way I've found to really explain it. In my first physics class metric (SI) was taught to us with a problem like "what's 2 x 10^2 withits?" Answer: 2 hecto-withits or "to heck with its."
US military design work is generally conducted using millimeters as the measure of length and kPa for pressure or area loadings; this is a pain as kPa simply is not an intuitive sounding unit of measure whereas kN/m^2 is.
RE: KIPS
Right on, e.u. is an entropy unit ≡ cal/oK/mol.
Same here, "I first heard the term "kip" in statics class many moons ago and was confused;" it was also where I first saw # as shorthand for pounds (force, not £).
Graduate school involved bars and MPa, but I stayed out of trouble by converting to atmospheres.
RE: KIPS
You need to know the basic units, but the calculator takes it from there.
RE: KIPS
The FEA result may say that stress is 32000 psi, and I have to compare with the yield of A36 steel... I know it's really easy, but it just gets to me. Stress analysis is hard enough without the extra hurdles.
tg
RE: KIPS
I don't really see the point in sticking with prejudice to an out dated unit system such as the inch-pound system (the so called empirical) that was good enough to be used in times when precision meant nothing.
I know engineers in the US , UK and some other countries may disapprove with me but come on guys, make way for the 22nd century!!!
Drop By !!
www.geocities.com/concretesite
RE: KIPS
It is commonly known that time is money, and knowledge is power. It is not so commonly known that these relations have a strong impact on the structure of our society. Hence:
time=money
knowledge=power
These relations can easily be substituted into the tried and true equation of work and energy:
power=work/time
Therefore:
knowledge=work/money
Solving for money:
money = work / knowledge
Conclusions:
Going back and putting "time" back in, it is clear that we work overtime only when we've done something dumb.
Also, those with the most power get there through doing the most work, but I disagree that they didn't also do it for the money.
STF
RE: KIPS
It is also fascinating is that the US Federal government (at least engineering and construction for the DOD) IS metric, but much (most!) of the USA is not.
Metric is "10 times" better!
RE: KIPS
I had the pleasure of working with an older British Engineer whom I have immense respect. He does not think that the metric system did not do wonders for the UK and they do use it.
The argument can be made for both systems. I think engineers should be trained and capable of using both systems.
RE: KIPS
Maybe the fact that the French "invented" the system has something to do with the USA not adopting it.
I have used both measurement systems in Australia, Canada and the USA. Metric "wins" IMO.
The $125 million NASA Mars Climate Orbiter mission may not have been "lost" in 1999 if the USA was fully and officially metric.
For the merits on the metric system, see the US Metric Associations FAQ's at:
http://lamar.colostate.edu/~hillger/qanda.htm
RE: KIPS
I have used both systems since grade school and continued to do so in my work now.
I really don't see the problem with using one or the other and why engineers of all people vehmently oppose the use of the metric system.
I do agree that it is logical to follow the units of world trade. However, the system seems to work despite the three countries who are holding on the english units.
RE: KIPS
To work logically on computers, decimal feet is the only way they can work internally and is also the easiest input method. Having to perform convoluted calculations just to convert feet, inches and fractions of an inch to decimal feet for input or for use in calculation is just plain stupid (there are 4 mathematical steps to do this, 4 mathematical symbols need to be input plus more numerical characters are required than for SI) when you can use a system where there are no such divisions, SI. m, cm or mm make like so easy for the person doing the input and for the program itself internally, simply move the decimal point to change between them.
It must have been horrendous using a slide rule or an abacus with imperial length units and it is nearly as bad with electronic calculators.
USA is not the only country thet would have to suffer a conversion process and the hassles with it. Australia, UK and Canada did it and so did many others and we all survived the experience and now I am glad we did. The SI system is much easier to work with, especially length units.
Fortunately this is one USA will not win in the long term, SI is the worldwide unit system and a couple of intransigent countries have not moved to it yet.
RE: KIPS
Like Qshake, I have used both imperial and SI units. At college (many years ago), I did an Ordinary National Certificate in Mechanical Engineering (in the UK) and the units were all imperial at that time. Later I went on to do a Higher National Certificate, but by this time the UK had gone metric and the units were SI. I have used SI units ever since and they are so much easier to handle. All the 10^6 and 10^3 etc. cancel out and you are left with just a simple sum to calculate. With the imperial system however, there is all that, divide by 12 to convert inches to feet and 1728 to convert cubic inches to cubic feet - what kind of numbers are those!! - to complicated!!
Keep it simple (KIS).
In reply to Lutfi - `cost of change over`. Although in theory the UK went metric 25 or 30 years ago, many of our steel sizes are in reality, still imperial sizes. Consequently we have steel `I` beams of, for instance, 457 x 191. This may sound an odd metric size (and it is), but is still, even after all these years, the old imperial steel rolls just converted to metric numbers (18" x 7.5"). Yes, many of our steels are still imperial in reality!! As you say, to expensive to change everything at once.
Regards,
Neilmo
RE: KIPS
1. In the US, who are the major proponents of going Metric? Those in the machine tool industry, the industry that will benifit the most because of the retooling required.
2. Ingenuity, from what I've read, the loss of the Mars Orbiter was due to someone using the wrong conversion factor between the Imperial and Metric systems. The person reviewing the Metric answer could not conceptualize the answer. We engineers rely on our ability to know what psf and psi mean physically. We loose that when we go to Metric units. I've seen too many mistakes made trying to convert units, even in some of the trade journals!
3. State DOT's have been converting to Metric measurements, why? We don't trade the roads with a foreign county! In fact, many of the DOT's have given up on the Metric conversions of reinforcing steel, it was just too confusing and lead to too many mistakes.
Use the conversions when you HAVE to, but leave those of us old fuddy-duddies who don't want to ALONE!
RE: KIPS
RE: KIPS
RE: KIPS
I go back and forth between the units, and see advantages to both. But to say that no part of the SI system is difficult or confusing - even when you are conversant in it - is simply wrong.
And as to the "rest of the world is right so the U.S. should change" argument: the last time I looked, WE were the ones doing most of the buying (hence our balance of trade problem.) Seems to mee that you'd use OUR measurement system - if you want us to buy your products!
RE: KIPS
RE: KIPS
Please help me here as I am trying to recall a recent book on the introduction of the SI system. Since I am trying desperately from memory to recall the issue I just can't put my finger on it...But wasn't there some error in the SI system for the meter?
Or did this have something to do with a survey of some land that was off due to an incorrect measurement...
It seems to me that two fellas set off to chart or record something and had a great deal of difficulty.
Well, I'm off to look that book up - I'll Be Back!
I just thought it might had some history to this thread.
RE: KIPS
The book is titled "The Measure of All Things" by Ken Alder.
Here is an excerpt of a review on Amazon...
"Alder delivers a triple whammy with this elegant history of technology, acute cultural chronicle and riveting intellectual adventure built around Delambre's and Mechain's famed meridian expedition of 1792-1799 to calculate the length of the meter. Disclosing for the first time details from the astronomers' personal correspondences (and supplementing his research with a bicycle tour of their route), Alder reveals how the exacting Mechain made a mistake in his calculations, which he covered up, and which tortured him until his death. "
Any comments, perspectives, historic views?
I was quite surprised to see this and have never known about it as long as I've worked with SI in grade school.
RE: KIPS
But I report soil unit weight in pcf and stress in ksf. All of my other "typical" reporting values are dimensionless!
RE: KIPS
It seems that the platinum-iridium kilogram standard kept in France is losing weight (cold-fission? champagne fumes?) by about 3 parts in 108 per century.
Does this mean the collapse of all Kg-based standards?
Abstract of NY Times article:
“Science Desk | May 27, 2003, Tuesday
Scientists Struggling to Make the Kilogram Right Again
By OTTO POHL (NYT) 1546 words
Late Edition - Final , Section F , Page 3 , Column 2
"In these girth-conscious times, even weight itself has weight issues. The kilogram is getting lighter, scientists say, sowing potential confusion over a range of scientific endeavor.
The kilogram is defined by a platinum-iridium cylinder, cast in England in 1889. No one knows why it is shedding weight, at least in comparison with other reference weights, but the change has spurred an international search for a more stable definition.” (http://query.nytimes.com/gst/abstract.html?res=F30E15F83C550C748EDDAC0894DB404482)
A more scientific story from NIST and efforts to create an electronic-based kilogram standard is at http://www.eeel.nist.gov/811/elec-kilo.html
Some Internet commentary is at http://www.metafilter.com/mefi/26061
RE: KIPS
I've seen size 40 shirts (40" or 101.6cm) that actually ranged in size from 38" to 44".
What about shoes, are the sizes related to length? Nope, well cannot possibly be when a size 10UK is about a size 12US which is about a size 9.5Aus.
Are the sizes related to metric or english? Are the sizes related to ego?
Thank god (or whoever you belive in) that we engineers have settle on two systems only, where an inch is an inch (which is 25.4mm) and where a kilogram is a kilogram (or 2.204622622 lb according to my HP15c), but hang in there I've also heard of a gallon and a US Gallon!
bye
sc
RE: KIPS
RE: KIPS
But what about "slugs" to make the mix stir.
These weighty things have lost their "g's",
For the masses just to please.
RE: KIPS
STF
RE: KIPS
Certainly ANSI defines all units in terms of SI.
The big problem is that the general population sees no value in switching units and, as previously stated, many industries are completely tooled in English units so the cost of changing is drastic.
As an aide, I worked for a company developing a new inspection system and we were going to be progressive and do it all in SI. The problem is that it was hard/expensive to get material in nominal SI units so we either ended up with lots of decimal cm/mm dimensions or having to machine material that we'd have normally used with stock dims.
Also, I once worked as a machinist at HP and everything we did was in mm.
A final difficulty: I now work for a micro-company whose products are mostly sold in SI countries. However, I still dimension everything in inches because we don't have DRO's on our mills and my machinists would keel over if they had to multiply/divide by 25.4 everytime they dialed in a table movement.
From a calculation viewpoint, I can't see why anybody would want to use English units.
Finally, I learned about kips in Strength of Materials in 1986...I never saw it in any of my ME courses, books, or handbooks - seems to be a CE unit mostly.
RE: KIPS
Slugs are your garden variety masses...
RE: KIPS
Redhead
RE: KIPS
I think that SI is better for ease of use and precision, but Imperial units "rule" for proportioning and layout. Hasn't anybody else muttered curses under their breath at the French when dividing something into three (equal?) parts????
Curvbridger
RE: KIPS
And if an engineer doesn't have a "feel" for things like the correct order of magnitude, then it's just a matter of time before they get into trouble on some design because they were precise and wildly inaccurate.
That's one thing the slide rule forced you to do and something that calculators and software don't do. We certainly need to take advantage of technology, but at the same time we need to know what it's doing and be able to recognize when accuracy is obscured (maybe even lost) in lots of precise calculations -
RE: KIPS
"It is better to be approximate and correct than precise and wrong."
RE: KIPS
Two items from my ezperience with SI system. 1) I saw dock "caissons" being designed (roughly 40m long) to riduculous numbers like 41131mm. 2) I saw an article in a national engineering/construction magazine where the title was something like "304mm of sand and gravel covers site for working platform for piling contractor" "Wow", I said. I would never know that working platforms are so "precise". Did the writer get the site engineer's comment as "a foot", then used his jim-dandy calculator and change 1ft to 12 inches, then 12 inches x 2.5 to get mm but, yeah, it should be a bit higher so I'll make it 304!!? Probably. ASCE has always sugested 305 as the equiv of a foot. But, then who's foot. Like the kg losing "mass", there are a number of different definitions of "foot", too.
Focht3 on his post previous to this has it right!
RE: KIPS
RE: KIPS
I think I forgot to carry a 3...
STF
RE: KIPS
If they know the Kg standard is changing, why don't they use whatever it is they are checking it with as the standard instead ? Why do they even need it ? Does anybody ever use it ?
p.s. - looks like you have to pay to read that article - typical NY Times.
RE: KIPS
There are 1.5 Hogsheads in a Puncheon. Unfortunately, a Puncheon is either 84 gallons of wine, or 54 gallons of beer. At least, both gallons are four quarts!
My reference is The Mechanic's Calculator, Second Edition by William Grier Civil Engineer, MDCCCXXXV.
An instructor I had in college insisted that we do unit balances in our calculations. The obvious objective is that when you work out your weight as 150sq.in/sec, you know you have screwed up somewhere. This makes unit conversions easier too.
Any time I have seen calculations done by Europeans, they have been in the CGS system. Is the SI system (as opposed to the metric system) really that popular out there?
JHG
RE: KIPS
Check out literature that quotes the strength of a grade_12.9 screw (metric). According to the web site I just checked, the 12 is the strength of the bolt in units of 100MPa. I believe that this is what my Machinery's Handbook 26th edition claims too.
I have seen literature listing the strength of these bolts in psi, and the conversion is not exact. It becomes exact when I use my Machinery's Handbook 21st edition for a reference. The number 12 is the strength of the bolt in units of 10kgf/mm^2. One kilogram force equals approximately ten Newtons.
Ref:
http://www.mech.gla.ac.uk/~paulk/pde/nutnbolt.htm
http://www.camcar.textron.com/NewHTML/grades.html
JHG
RE: KIPS
Could I switch? Of course. I grew up in a canadian school, and spent the first 20 years of my life in metric, until I came into contact with REAL machines. The dichotomy of canadian education vs. technology underpins my belief that theory and practice are two different things.
The choice between SI and CGS is also determined by industry. I would expect engineering to make more sense in Kg/meters, while chemistry would find grams much more useful.
I use MathCAD all the time for my analyses. It makes the units work effortlessly. It can switch between all three systems easily.
STF
RE: KIPS
RE: KIPS
Like many I’ve work with both and seen many of the aforementioned conversion mistakes. Leaving off the suffix or changing units in midstream are quite common.
A problem that I’ve seen locally is the convention of using of SI units in dimensioning. I worked on two large scale chemical plants that were designed and had some components constructed in Europe. All dimensions on the drawings were in millimeters (6000,9000,etc.). They are teaching in schools to change to cm’s, etc. Print in hand I tried to show the instructors at a technical school and Jr college this and got a response of, What are you trying to do confuse the issue.
A very good conversion program is "Conversion Buddy" by Jim Presley. He also has a another program Expression Buddy.
You can dictate the accuracy in Conversion Buddy.
They are available as a free download at:
http://metrologyforum.tm.agilent.com/download4.shtml
RE: KIPS
Pretty handy, most things are already built in, plus you can add custom conversions.
And its FREE!
http://www.joshmadison.com/software/convert/
RE: KIPS
RE: KIPS
25 links = 1 rod
4 rods = 1 chain
10 chains = 1 furlong
8 furlongs = 1 mile
3 miles = 1 league
1 furlong x 1 chain = 1 acre
640 acres = 1 square mile
Thanks goodness for metres and hectares!
RE: KIPS
I hope that engineering schools are NOT teaching people to use centimeters for dimensions!
In an environment where people use both english and metric dimensions, they have to look different. Millimeter and inch dimensions are hard to confuse. I am not so sure about centimeters and inches.
The nice thing about millimeters is that for a lot of stuff, you lose fractions and decimals.
JHG
RE: KIPS
Maui
RE: KIPS
1 poundal = the force that accelerates a pound mass one foot per second per second. (1 poundal= 1 lbm*ft/sec/sec)
The only legitimate argument for converting to SI is that everyone else is doing it. The guy that posted the thread couldn't convert from kips to newtons--hopefully he's not designing anything important.
Viva la difference!