# GonPer

Members

52

1

## Reputation Activity

1. GonPer liked a post in a topic by Q.Nguyen-Dai in Variable Pressure in Optistruct
Define a local cylindrical system for your tube. Presuming that your pressure varies from 0.055 MPa to 0.55 MPa over 180° along circumference, your equation is something like:

p = 0.055 + 0.495 * y / 3.14159
( y = 0.0 .. 3.14159 rad , y is circumferential direction)

You enter only right side of this equation into Analysis => Pressure => equation. Don't forget to select your local cylindrical system thanks to the button "system".

2. Jahnavijikki liked a post in a topic by GonPer in finding 2d elements
Hi Jahnavijikki,

Go to tool - delete - elems - by config (CTRIA3) - select entities

Best regards,

GonPer

3. GonPer liked a post in a topic by Rahul R in DIfference between ESE and strain energy
Regarding Strain Energy & Strain Energy (Density) here is some more info.

The units of energy are force*distance, so when a load is applied and the material deforms, we are putting energy into the material. This energy introduced into the material due to the loading is referred to as “strain energy.” We prefer to normalize strain energy by unit volume, and when we do so, this is referred to as strain energy density. The area under a stress-strain curve is the energy per unit volume (stress*strain has units of force per area such as N/mm2 , which is the same as energy per unit volume N-mm/mm3 . We will be assuming linear elastic material only. Most metals and alloys are linear elastic prior to the onset of plastic deformation, so this is a valid assumption.

Though Element Strain Energy is a good measure to watch in Modal analysis, as it gives an idea on the area of concern & to go for the mesh refinement there as ESE in modal analysis is somewhat similar to what Stress in Static analysis.

But if we go for Static/Structural analysis then Strain Energy Density could give you an idea on what elements/area of your model are contributing more in taking the load (absorbing). This same factor is used in optimization as well, where the load-paths are identified where the model have high strain energy density. So basically you get idea where you should strengthen your part. High stresses & High strain energy could be on common areas in some cases but not always guaranteed.

So better to go for Stress results when your main concern is Stress (which is there in most of the cases). But when your main concern is Stiffness of the structure i.e you want to limit the deflection/displacement happening in your structure then you may want to stiffen your part wherever it is showing high strain energy density.

Just to add, Strain Energy Density dependent function is also the main criteria on which Hyperplastic materials are based, as the behavior of Hyperelastic materials can’t be described with a single modulus like we describe for a general elastic-plastic material.

http://www.altairhyperworks.com/hwhelp/Altair/hw14.0/help/hwsolvers/hwsolvers.htm?ese.htm

4. GonPer liked a post in a topic by tinh in 1d elements with varying cross section
yes, i think you should use 3d mesh if you need to capture detail your structure
5. tinh liked a post in a topic by GonPer in 1d elements with varying cross section
Hi,

I've been looking into the reference guide and I found this statement:
6 - For tapered beams, a single prismatic beam is created with dimensions obtained by
weighted averaging of all station dimensions.

So I guess this element will not be very helpfull for my need.

Sorry for re-opening the topic.

Best regards,

Gonçalo

6. GonPer liked a post in a topic by tinh in 1d elements with varying cross section
hi,
try setting field SO(i) in pbeaml card, it is for stress output
7. Rahul R liked a post in a topic by GonPer in 1d elements with varying cross section

Best regards,

Gonçalo
8. GonPer liked a post in a topic by Rahul R in 1d elements with varying cross section
PBEAML card and defined different section .As far as I know, tapered beam sections cannot be rendered in 3D for visulaztion.Check user guide for detailed information.Also if possible you can share hm or fem file for better understanding.

9. GonPer liked a post in a topic by tinh in 1d elements with varying cross section
DIMA is cross section' size at node A and X/XB is distance from A/length
so you dont need to set x/xb=0 , just set x/xb=1 for tapered beam
visualization will not show tapered shape, as Rahul commented
×
×
• Create New...