Section Modulus calculation and optimization

AIM- To increase the section modulus of a given hood by necessary changes

TOOL USED- NX CAD

MATERIAL USED- STAINLESS STEEL AISI 302

INTRODUCTION- 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 design include area for tension and shear, 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. Equations for the section moduli of common shapes are given below.

z= Section modulus

I= Area moment of inertia

Y= Distance from neutal axis to the outer most fiber of a material

Area moment of inertia- It signifies the tendency of cross ection to resist bending. Greater its value greater is its tendency to resist bending.It is given by-

Elastic section modulus- The elastic section modulus is used in the design application of structural member which determines the resistance to bending as within elastic limit as per the stress-strain curve. The failure of the component is considered in the elastic region.

So to keep our desin values within elastic limits we will use minimum value of moment of inertia because from here itself material will start to deform.

EXISTING HOOD SECTION-

Results obtained are as follows-

I_MIN = 2.91e+05 mm⁴

^{A= 1.42e+03 mm2}

^{Y= 441 mm}

^{From bending equation-σ/y=M/I=E/R}

^{S = I/Y S= section modulus.}

^{I= Minimum principle moment of inertia.}

^{y= Distance of the outer most fibre from neutral axis.}

^{So by pluging in these values}

^{S= 2.91e+05/441= 659.86 mm3}

^{MODIFIED SECTION- By incorporating more embosses and increasing in area can increase our moment of inertia because according to formula of moment of inertia more the distance of area from neutral axis greater will be its inertia so keeping that thing .}

Results-

I_{MIN = 4.53e+05 mm⁴}

_{A= 1.51e+03 mm²}

Y = 441 mm

_{^{S= I/Y= 4.53e+05/441 = 1027.21 mm3}}

FINAL RESULT- Thus stifness of the car hood has been increased by increasing its moment of inertia.