Section Modulus calculation and optimization

SECTION MODULES CALCULATION

OBJECTIVE :

To calculate the section modulus of the hood panel and then optimizing the hood panel for better section modulus.

Section modulus:

• Section modulus is a geometric property for a given cross-section used in the design of beams or flexural members. Other geometric properties used in the design include an area for tension and shear, the radius of gyration for compression, and moment of inertia and polar moment of inertia for stiffness. Any relationship between these properties is highly dependent on the shape in question.
• It is termed as the ratio of the second moment of inertia and distance from N.A (Neutral axis) to the extreme fiber. Also, it is the measure of the strength of a given member. The stress in the outermost section of the beam is computed with the help of section modulus. It is indicated by S.
• Section modulus is indicated as follows:
• Section modulus is indicated as follows:
• S=I/Y
• S = Section Modulus
• I = Moment of Inertia
• y = distance between the neutral axis and the extreme end of the object

First analyze the base section :
case-1

FORMULA USED :

• max MOI = 4.806736666e + 06 [mm*4]
• min MOI = 1.611296964e + 04 [mm*4]
• H = 646.4811 , y = H/2 : y=323.24
• section modulus S = I/y
• FOR first analysis of max MOI S = Imax/y
• =4.806736666/323.24
• =14.87e+03 mm*3
• for first analysis of min MOI S = Imin/y
• = 1.611296964/323.24
• S =49.84mm*3

case-2 :
by adding +0.5 mm in the depth of hood

• max MOI = 1.643234871e + 06 [mm*4]
• min MOI = 5.508407288e + 03 [mm*4]
• H = 646.4811 , y = H/2 : y=323.24
• section modulus S = I/y
• FOR first analysis of max MOI S = Imax/y
• =1.643234871/323.24
• =5.08e+03 mm*3
• for first analysis of min MOI S = Imin/y
• = 5.508407288/323.24
• S =17.04mm*3

FIND RESULT ;

Thus the stiffness of the car hood has been increased by increasing its area moment of inertia.

CONCLUSION :

• Section modulus is directly dependent on the area moment of inertia and the distance from the neutral axis. Hence, to improve the geometry of the carry more bending load, the section modulus can be improved by increasing the area MOIof a given section.We can increase the section modulus just increasing the gap between the outer & inner panel.