Upload
mehranzaryoun65
View
15
Download
1
Embed Size (px)
DESCRIPTION
Describe how Marc’s user subroutine UACTIVE is currently being employed as an instrument for instruction in the area of sheet metal blanking modeling.
Citation preview
Projects for Mechanics of Metal Forming Courses: A Look at User Subroutines for Formability Assessment
Dr. Lorenzo M. SmithOakland University, Rochester, MI
OBJECTIVE Describe how Marcs user
subroutine UACTIVE is currently being employed as an instrument for instruction in the area of sheet metal blanking modeling.
BACKGROUND
Lift Gate Outer
BACKGROUND
Failure originating from an edge remains a significant concern.
BACKGROUND
The sheet metal blanking process is similar to three- hole punching of a piece of paper.
COURSE PROJECT
M.E. 571: Theory of Plasticity
M.E. 578: Mechanics of Metal Forming
M.E. 678: Advanced Metal Forming
COURSE PROJECT
COURSE PROJECT
COURSE PROJECTMain Components of the Course
Classical Theory of Plasticity (Overview)
Failure Criteria
Stretching
Bending
Drawing
Stretch-Bend-Draw
COURSE PROJECT
How can Marc be used to help the students explore the modeling of sheet metal blanking?
COURSE PROJECT
50% True Effective Strain Failure Criterion
(One of many possible ductile fracture criteria)
COURSE PROJECT
COURSE PROJECTFar in excess of 50% effective strain
COURSE PROJECTStill.no separation! Another approach is needed.
COURSE PROJECTsubroutine uactive(m,n, mode, irststr, irststn, inc, time,
1timinc)c c implicit real*8 (a-h,o-z) dp
include '../common/implicit'dimension m(2), stress(1), strain(1), epten(6,28)include '../common/space'include '../common/elmcom'include '../common/heat'include '../common/strvar'
cc failure criterion for shearing of sheet metalc m(1) = element number, m(2) = master element number inc the adaptive analysis, n = internal element number,c inc = increment number, time = time at beginning ofc increment, timinc = incremental timec Also, nn = integration point number which is available c through include 'lass'c Also note key element info is available through include 'elmcom'c Required Output:c mode = -1 to deactivate elementc mode = 2 leave in current statusc mode = 1 activate elementc irststr - set to 1 to reset stresses to zeroc irststn - set to 1 to reset strains to zerocc
call elmvar(7, m, 1, 1, xx)
if (xx.gt.0.50)thenwrite(*,*) "Element Removed. Effective Strain = ", xx mode = -1endif
If the effective strain exceeds 50%, then remove element.
UACTIVE Subroutine
COURSE PROJECT
COURSE PROJECT
COURSE PROJECT
CONCLUDING REMARKSThe automotive industry relies heavily upon numerical modeling of metal forming/cutting.
The use of Marc within the context of a graduate-level course at OU, has helped academia prepare engineers for the challenges associated with sheet metal blanking.
Dr. Lorenzo M. SmithEmail: [email protected] Tel. (248) 370-4629
Slide Number 1OBJECTIVEBACKGROUNDBACKGROUNDBACKGROUNDCOURSE PROJECTCOURSE PROJECTCOURSE PROJECTCOURSE PROJECTCOURSE PROJECTCOURSE PROJECTCOURSE PROJECTCOURSE PROJECTCOURSE PROJECTCOURSE PROJECTCOURSE PROJECTCOURSE PROJECTCOURSE PROJECTCONCLUDING REMARKSSlide Number 20