Section Modulus calculation and optimization
WHAT IS SECTION MODULUS :
- SECTION MODULUS IS A RATIO OF MOMENT OF INERTIA (I) OF A GIVEN CROSS SECTION TO THE DISTANCE FROM THE NEUTRAL AXIS (Ymax)
S = I / Y
WHERE , I = MOMENT OF INERTIA
Y = DISTANCE FROM NEUTRAL
- INERTIA : A TENDENCY TO DO NOTHING OR TO REMAIN UNCHANGED.
- AREA MOMENT OF INERTIA : THE AREA MOMENT OF INERTIA IS A PROPERTY OF A TWO DIMENSIONAL PLANE SHAPE WHICH CHARACTERIZES ITS DEFLECTION UNDER LOADING.
- FOR DIFFERENT SHAPES WE HAVE DIFFERENT MOMENT OF INERTIA
SECTION MODULUS CALCULATION IN HOOD :
- FOR THE GIVEN CASE WE ARE CALCULATING SECTION MODULUS FOR THE HOOD WE DESIGN EARLIER.
- HOOD IS FRONT MOST PART OF THE VEHICLE , SO CONSIDERING OF FRONTAL CRASH THE IMPACT WILL BE FIRST AFFECT THE HOOD.
- WE NEED ENSURE THE IMPACT MUST NOT GO INSIDE THE PASSENGER COMPARTMENT.
- HOW WE CAN ENSURE THAT? WHAT IS STRENTH OF OUR HOOD ? WILL IT SUSTAIN THE LOAD ? , THE ANSWER OF THESE QUESTION WE CAN FIND FROM SECTION MODULUS.
- FIRST WE START TAKING SECTION FROM HOOD PANEL.
- SO WHAT I DID IS I HAVE A DATUM PLANE AT THE CENTER OF THE HOOD AND FROM THERE GOT A INTERSECTION CURVE.
- NOW , WE CAN NEED TO CHECK THIS SECTIONS INERTIA ANALYSIS BECAUSE IT AS SOME STRENGTH WE NEED FIND OUT HOW MUCH IT IS.
- SO I PERFORMED SECTION INERTIA ANALYSIS ON THIS SECTION AND FOUND OUT FOLLOWING RESULT.
- SO WE GOT THIS DATA WERE I HAVE MAX. AND MIN MOMENT OF INERTIA , WE NEED TO FOCUS ON MIN. MOMENT OF INERTIA BECUASE AS IT DIRECTLY PERPORTIONAL TO CROSS SECTION AREA.
- AND AS OUR CROSS SECTION AREA INCREASE WE INCREASE MOI ANIT WILL INCREASE SECTION MODULUS , THIS LEAD TO INCREASE STRENGTH OF OUR MATERIAL.
- SO WE GOT INITIAL DATA OF OUR PREVIOUS DESIGN CONSIDER THIS AS CASE 1
CASE 1 : PREVIOUS HOOD DESIGN.
MOI (MAX) : 4.816666315 MM4
MOI (MIN) : 1.667960566 MM4
- NOW , I IMPROVED MY DESIGN TO INCREASE MOI INITIALLY TO ONCREASE STRENGTH
CASE 2 : IMPROVED DESIGNED.
- THE MAJOR FACTOR OF INCREASING STRENGTH IS ADDING EMBOSS TO THE MATERIAL
- BY ADDING EMBOSS WE ADD MORE MATERIAL TO OUR COMPONENTS THIS LEADS TO IMPROVE ITS STRENGTH.
- AND ALSO INCREASE CROSS SECTION AREA.
- IN THE ABOVE IMAGES YOU CAN SEE TWO DESIGN , ON THE LEFT SIDE IT IS PREVIOUS DESIGN AND ON THE RIGHT SIDE IT IS IMPROVED DESIGN.
- WHAT I DID IS , I SIMPLY EDITED MY PRVIOUS EMBOSS AND INCREASED THE AREA OF SECTION.
- THIS THING I NEED ON FOUR SIDES , AND MAKED SOME CHANGES IN THE EMBOSS.
- AFTER THAT I PERFORM SECTION INERTIA ANALYSIS ON THIS IMPROVED SECTION AND FOUND FOLLOWING RESULTS.
- YOU CAN SEE NOW THE MOI (MIN) IS BEEN INCREASED BY SOME VALUE.
- I ALSO MEASURED THE DISTANCE FROM THE NEUTRAL AXIS.
- SO NOW I HAVE MOI VALUE AND DISTANCE FOR MY TWO CASES , I CAN CALCULATE SECTION MODULUS FOR THIS DESIGN.
- WE HAVE TO CONSIDER Y/2
SECTION MODULUS CALCULATION FOR CASE 1 :
S = I/Y
= 1.667960566 / 440.5478
= 0.003786
SECTION MODULUS CALCULATION FOR CASE 2 :
S = I/Y
= 1.770737069 / 440.5478
= 0.00402
- WE CAN FIND THE DIFFERENCE ITS INCREASE SECTION MODULUS VALUE , AS MOI INCREASES SECTION MODULUS INCREASES AND IMPROVE OUR STRENGTH.
- SO I CONCLUDE THAT BY IMPROVING MY DESIGN , MY IMPROVED SECTION IS HAVING MORE STRENGHT COMPARE TO PREVIOUS.