Challenge

Week - 5 - Modelling Spotwelds

KKannan Saravanan24 Jul 2020

G-DRIVE=> https://drive.google.com/drive/u/0/folders/1S18pT4BTUAOJ-_CcfmpdcvvKG5dY2Guq

Aim

To create the spot weld with beam and solid(hexa) with the force method and time base failure method and comparing the result and evaulate the result obtained from graph.

WHAT IS WELD

Join together (metal parts) by heating the surfaces to the point of melting with a blowpipe, electric arc, or other means, and uniting them by pressing, hammering, etc.

WHEN THE WELD FAILURE CRASH TEST

During the impact the huge amount shock wave is travelled from one end to other end. during the time the shock wave which have more energy contains like internal energy and kinetic energy at that time when the two parts are join together(spot weld) the huge ammount of energy transfermation the weld will chance to get fail

And also all the weld is not to fail at the impact test some of the weld may not fail the failing is based on the axial and shear force acting on the material and the weld material propert

HOW TO CALCULATE THE WELD FAILURE IN SLOVER(CAE)

There is servel method of calculate the weld failure here we saw about the TIME BASE and FORCE BASE

TIME BASE
- The time base method we get already test result and find when the time the weld are failed from there we give the slover. In particular time my weld need to fail and at the what is axial force and shear force of the weld.
FORCE BASE
- The force base method is onther way of finding the weld failure. in this case we assign failure force such as Axial force resultant,Force resultant ,Force resultant NrtF at failure.,Torsional moment resultant Mrrf at failure. Moment resultant MttF at failure. based on the force when the force is exceding the weld get failed.

MODELSETUP REQUIRED OF GIVEN PART

weld craetion
section creation
material craetion
define the type of failure
contact defination
constrained defination
control defination
data base creation
post processor

SPOT WELD CREATION WITH TIME BASE METHOD(WITH OUT CONSTRAINED)

EDIT PART DATA

the given part is name edited as our convineent as a R-part(red),and B-(blue) part

WELD CRAETION(SPOT BEAM)

go to the element and mesh>element generation>beam>beam by:two node set>create
for this assignment we create 7 spot weld beam and during the cration uncheck the pick pid box

SECTION CRAETION

the beam section of element formulation is 9-spotweld beam, see *MAT_SPOTWELD (Type 100). and the QR/IRID is 4 which is quadrature rule 4 the thickness is 2.5
the shell section is element formulatiom is 16 which is fully integrated and the NIP number of integration point is 4 the thickness of shell is 1.5

MATERIAL CRAETED

As we seen the last assignment propert is used for this also for shell part
As we take as a apot weld is steel meterial and the failure time is 2.5 ms because this the time base failure

CONTACT DEFINATION

for the spotweld connection we give first tied shell contact this basic spot weld contact where as the slave node is being connect with the beam elemnt and the master is part set (r part,b part).
we used onther card automatic single surface card to avoid the penittration

CONTROL DEFINATION

we use the basic control defination card with the temination time of 5ms

DATA BASE DEFINATION

to find the spot weld force we give the swforc in asscii cards
other general use cards

RAWLL CRAETION

TYPE TWO METHOD- FORCE BASE

In force base method we can just add some axila and moment force as given image

RESULT:(TIME & FORCE BASE)

TIME BASE AXILE FORCE FAIL

- fig 1
- fig 2
- fig 3
The above seen image is a time base spot beam weld fail. we gave 2.5ms failure time. when the part hit on the wall at time of 2.1 the stress in crease as per the fig-1. at the same time the weld axile force also increase based on the next time step and velcoity. but the time of 2.5 the stress will be on there part due to the high impact between rwall and part the force between the welded part is zero why it happned means we given TFAIL=2.5 based on that it would be react alll the weld are failed it shown in the image of fig 2
As the same time t=2.1 the force is contionusly increase upto the 2465N. after the failing time of 2.5 the force are suddely reduced why it happended because of the low time step the stress start with 2.1 and ends with 2.5 there is 0.4 time step only so,that the force is suddenly reduced

FORCE BASE AXILE FORCE FAIL

- fig 1
- fig 2
- fig 3
- fig 4
As pere the fig-1 the time =2.1 the box is hitting on the wall at the time the force of the part is 421.1N/mm2 at the time there is now weld are failed as we seen the fig-2 the time of 3.1 the maximum stress are occur because of the force acting on them but there two more weld are still absorbing energy in fig-3 the time of 4.0 the stress of the part is 957.18N/mm2 at the end of the time step t=5 the stress is 885N/mm2 the stress reduced because of weld faild and energy dispation

we give the axile force ,resultant force,momentanum force at the mat card based on the that behaveiour it fails as pere the fig-1 the time =2.1 the box is hitting on the wall at the time the force of the part is 1641 N at the time there is now weld are failed as we seen the fig-2 the time of 3.1 the maximum weld are failed because of the force acting on them but there two more weld are still absorbing energy because the axile force is not execding what we value given in mat crads in fig-3 the time of 4.1 the reamin weld also faild it indiacte the force are exceding what we gave in the mat card.from this the actaul force acting on the weld is 4688.6N weld id 110016

VIDEO OF FORCE BASE_BACK SIDE

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TIME BASE ACCLERATION FORCE DIAGRAM

The above image acceleration of the indicated node during the impact with the rwall and part the acelaeration of the node is 502619 only invrease other node is getting down it why happened mean. when the part hiting the wall the next time stepthe part will rebounce that means acceleration nodes is retardation which means the de-accleration. in next time step th eblue part is moving forward along with the red part.so,the acceleration of the node with indicated the zig-zag maner after failing the node at time of 2.5ms the aceleration of the nodes are present so,that the graph which indicated the zig-zag manner.
From this graph the maximun acceleration is 3130 mm/ms2 onthe other hand -1478.3 mm/ms2 is a deacceleration of the nodes.

FORCE BASE ACCLERATION FORCE DIAGRAM

the above image indicate the force base of aceleration node in time base the 502619 is peak acceleration but the actually the 504430 id is the original peak acceleration node of the weld.when the part hiting the wall the next time stepthe part will rebounce that means acceleration nodes is retardation which means the de-accleration. in next time step th eblue part is moving forward along with the red part.so,the acceleration of the node with indicated the zig-zag maner after failing the node at time of 2.5ms the aceleration of the nodes are present so,that the graph which indicated the zig-zag manner.From this graph the
maximun acceleration is 5804 mm/ms2 onthe other hand -1478.3 mm/ms2 is a deacceleration of the nodes.

TIME BASE VELCOITY FORCE DIAGRAM

The velocity of the given part is 13.8 the - indicate the direction axis at the time 2.4 ms the velocity is remain constant but the time step2.5ms the colision happen and the velcoity reduced from 13.8 to 6.86 mm/ms

FORCE BASE VELCOITY FORCE DIAGRAM

TIME BASE INTERNALvs EXTERNAL DIAGRAM

Internal energy is defined as the energy associated with the random, disordered motion of molecules. It is separated in scale from the macroscopic ordered energy associated with moving objects; it refers to the invisible microscopic energy on the atomic and molecular scale.As we seen the graph phone IE and KE time 0 the energy also 0 which indicate there no energy dissipation between phone and impacter but time 3.2 there is contact hapening between the phone and plate so, that the energy dissipation occur so,that internal energy of the phone is increased after some time the it come the low value due to the the phone is bounce and no contacting between them and also the stress is evenly distrubuted around the parts
the kinetic energy (KE) of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its started velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes.in the same way but the energy dissipation happening for kinetic energy

FORCE BASE INTERNALvs EXTERNAL DIAGRAM

RESULTS(FORCE&TIME BASE SOILD WELD)

THIS IS TIME BASE FAILURE VIDEO

TIME BASE AXILE FORCE

- FIG 1
- FIG 2
- FIG-3
The above seen image is a time base soild weld fail. we gave 2.5ms failure time. when the part hit on the wall at time of 2.1 the stress in crease as per the fig-1. at the same time the weld axile force also increase based on the next time step and velcoity. but the time of 2.5 the stress will be on there part due to the high impact between rwall and part the force between the welded part is zero why it happned means we given TFAIL=2.5 based on that it would be react alll the weld are failed it shown in the image of fig 2
As the same time t=2.1 the force is contionusly increase upto the 2313N. after the failing time of 2.5 the force are suddely reduced why it happended because of the low time step the stress start with 2.1 and ends with 2.5 there is 0.4 time step only so,that the force is suddenly reduced

FORCE BASE AXILE FORCE(sloid)

- fig 1
- fig-2
- fig 3

we know that the soild wels is much stronger than the spot weld.As pere the fig-1 the time =2.1 the box is hitting on the wall at the time the stress of the part is 417.1N/mm2 at the time there is no weld are not failed due to the weld is soild element and there material property in the t=2.5 the stress of part ismore high 1615.81n/mm2 in fig-2 which indicates the more stress element is stretch together with helpof soild joint and the time of t=2.5 the stres of the part is 847.376n/mm2 in fig-3
At the same time when look into the axial force diagram the t=2.1 ms the force are increased it shows the the part is hitting the rwall like wise the weld axile force continusally increased at the time 2.5ms higly increased and it reduce gradually i.e the part will be bounce it self and it try come rest so,that the node number110025,110022 axile force is negative sign indicates and the time=5ms still the weld are alive that means the weld are no one is fail for as given force in the mat cards.the maximun axile force is 3779.8N at time of 2.5ms in the weld id is=110025

TIME BASE ACCLEARTION OF NODE

the above image indiacte the accleration of the spold conncetion element at the time=2.1 the acceleration elemnt starts after hit the part the part is come back at the time the part is highly deform as seen the video at the the acceleration of spotweld area undergone to the de accelartion show that that only the graph is zig zag mannerat time fail in 2.5ms the weld get fail but the accleartion of the weld elemnt ids not get rest under interia force so that the graph after the 2.5ms also still zig-zag manner.
the max acceleration is 1150.3mm/ms2

FORCE BASE ACCLEARTION OF NODE

the above image indiacte the accleration of the spold conncetion element at the time=2.1 the acceleration elemnt starts after hit the part the part is come back at the time the part is highly deform as seen the video at the the acceleration of spotweld area undergone to the de accelartion show that that only the graph is zig zag mannerat time fail in 2.5ms the weld get fail but the accleartion of the weld elemnt ids not get rest under interia force so that the graph after the 2.5ms also still zig-zag manner.
the max acceleration is 1305.5mm/ms2

TIME BASE VELCOITY OF NODE

the velcoity of the part is 13.8mm/ms the negative sign indicate the axis of direction upto 2.1 ms the velcoity remain constant when the part is hit onn the wall the velcoity is reduced from the 13.8 and then increase greadually.which indicate the velcoity not comes in still zero and the body is still moving so,that the nodes graph in zig zag manner
the max velcoity is 8.3mm/ms

FORCE BASE VELCOITY OF NODE

TIME BASE KE vs IE

Internal energy is defined as the energy associated with the random, disordered motion of molecules. It is separated in scale from the macroscopic ordered energy associated with moving objects; it refers to the invisible microscopic energy on the atomic and molecular scale.As we seen the graph phone IE and KE time 0 the energy also 0 which indicate there no energy dissipation between phone and impacter but time 3.2 there is contact hapening between the phone and plate so, that the energy dissipation occur so,that internal energy of the phone is increased after some time the it come the low value due to the the phone is bounce and no contacting between them and also the stress is evenly distrubuted around the parts
the kinetic energy (KE) of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its started velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes.in the same way but the energy dissipation happening for kinetic energy

FORCE BASE KE vs IE

CONCULSION

Through this assignment we larn the method of weld and how create and defination of spot weld materilas cards etc..
through this assignment we learn the how weld are fails in the time base and force base method
Through this assignment we identify the behaveiout of the spot weld and sloid weld and the acceleration,velcoity,KE,IE etc..

Week - 5 - Modelling Spotwelds

Ship work like this
in your own course.

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Ship work like thisin your own course.

Talk to a career counsellor

Ship work like this
in your own course.