Register to reply

Units assistance for loading of parts

by Corsan
Tags: assistance, loading, parts, units
Share this thread:
Corsan
#1
Mar28-12, 02:23 PM
P: 13
Hi all,

I am building a model in Abaqus and wondered if somone could assist with the units I need to enter.

I have built my parts using mm as the dimension, i.e. part is 10 units (mm) wide.

(To clarify this can also be entered as metres as in 10e-3, however I chose to be consistent with the mm approach).

Then for my material data I have entered my mass as 0.0025 (which was 2.5g/cc).
Youngs Modulus as 72000 and for the Plastic data I have entered my yield stress data as MPa (such as 425 with a plastic strain of 0.0090 (mm-3)).

As I wasn't consistent in using the SI measurements for mm (e-3) does this have a knock on effect for the above data?

Now for my loading of my parts can anyone clarify what I will need to enter for a 5000N load (pressure force)?

Thanks in advance
Phys.Org News Partner Engineering news on Phys.org
Researchers find security flaws in backscatter X-ray scanners
Virtual reality guides those whose memory is failing
Intelligent navigation system to personalise shopping trips
nvn
#2
Mar30-12, 12:57 AM
Sci Advisor
HW Helper
P: 2,124
Corsan: 2.5 g/cm^3 is called density, not mass. Enter your density in units of tonne/mm^3; i.e., 2.5e-9 tonne/mm^3, where 1 tonne = 1000 kg. Everything else you did currently sounds correct, except perhaps for strain. Applied force is called force, not pressure force. Pressure is in units of MPa. Enter your applied force in units of newtons; i.e., 5000 N. In summary, use N, mm, MPa, tonne.

Strain is dimensionless. Therefore, strain does not change, regardless of the units. Therefore, I am not sure why you wrote mm^-3 after your strain value.

By the way, always leave a space between a numeric value and its following unit symbol. E.g., 5000 N, not 5000N. See the international standard for writing units (ISO 31-0). Or see any credible text book.
Corsan
#3
Mar31-12, 09:13 AM
P: 13
Quote Quote by nvn View Post
Corsan: 2.5 g/cm^3 is called density, not mass. Enter your density in units of tonne/mm^3; i.e., 2.5e-9 tonne/mm^3, where 1 tonne = 1000 kg. Everything else you did currently sounds correct, except perhaps for strain. Applied force is called force, not pressure force. Pressure is in units of MPa. Enter your applied force in units of newtons; i.e., 5000 N. In summary, use N, mm, MPa, tonne.

Strain is dimensionless. Therefore, strain does not change, regardless of the units. Therefore, I am not sure why you wrote mm^-3 after your strain value.

By the way, always leave a space between a numeric value and its following unit symbol. E.g., 5000 N, not 5000N. See the international standard for writing units (ISO 31-0). Or see any credible text book.
Thank you for the response, that was exactly what I was looking for.
Appreciate the tip on units too


Register to reply

Related Discussions
Converting radiometric units (W/m^2) to photometric units (Lux) Advanced Physics Homework 0
Converting units in scientific notation to other units. Precalculus Mathematics Homework 5
FAQ:What's the differences between Radiometric Units and Photometric Units? Introductory Physics Homework 2
Loading swf Computing & Technology 15
Maxwell related equations converted from MKSA units to Gaussian units Classical Physics 2