Wednesday, 10 October 2018

Hi Every one welcome to my engineering blog.I am glad to introduce that we are starting new video series  fully dedicated to FEA and CAE field . Manly we will cover some journal topics based on  Hypermesh and Ansys Workbench software with theoretical concept.Hopeing that you will support the chnanel.

Soon I will provide the youtube channel details.

Keep Supporting. Thank you !!!!!!!

Monday, 1 January 2018

Thin walled Pressure vessel Concept

Thin walled Pressure vessel:-

What is pressure Vessel?

Pressure vessel is defined as closed cylindrical or spherical container which is designed to hold or to store fluids at pressure substantially different from ambient pressure.


Classification of Pressure Vessel.


1.based on d/t ratio:-


1.Pressure vessel whose d/t ratio is greater than 20 units, such type of vessel is categorized to Thin walled pressure vessel (d/t 20).
Ex. Boiler shell, LPG cylinder pressure cooker, storage tank 
terminology in pressure vessel


2.  Pressure vessel whose d/t ratio is less than 20 units, such type is called as Thick walled pressure vessel (d/t 20).
Ex. Hydraulic cylinder, gun Barrel, Storage tank under high pressure


2. Based on Shape of shell



1.   Cylindrical pressure vessel
2.   Spherical pressure vessel

DO comment !!!!!!

1.Why Spherical vessel better then cylindrical pressure vessel?
2.Which vessel we should used for safety purpose?
3.Which vessel we should used, keeping manufacturing cost in  mind?



Bursting of  pressure vessel occurs circumferential. 




Condition-1

At particular pressure, when longitudinal stress in thin walled pressure vessel is greater than ultimate strength, circumferential bursting occurs in pressure vessel.

σL> sut

FF = FR
longitudinal stress
  

FF= D2 P)/4-------------------------------i

FR= σLxπ𝐷x𝑡--------------------------ii

D2 P)/4 = σLxπ𝐷x𝑡

σL= σ2= σlongitudinal = pd/4t = σ1/2


Bursting of  pressure vessel occurs longitudinally.

 


Condition-2


At particular pressure, when Hoops stress in thin walled pressure vessel is greater than ultimate strength, bursting occurs longitudinally in pressure vessel.

σh> sut
FF = 2xF
hoops  stress diagram


FF= PxLxD-------------------------------i
FR= 2xσhxLxt--------------------------ii
PxLxD= 2xσhxLxt 

σh = σ1 = σhoop = pd/2t

Thin pressure vessel can be considered bi axial state of stress (due to longitudinal stress).


Bi axial state of stress diagram


σ1 = σhoop = pd/2t

σ2 = σlongitudinal = pd/4t = σ1/2


In plane τmax


=(σ12)/2 = pd/8t


Absolute τmax

=σ1/2 = pd/4t


Strain stress



Major principal strain 


ε1hoop= δD/D----------i

ε1= 1/E [σ1-μσ2]-----ii

σ2 = pd/4t = σ1/2

Equating i & ii

εh=δD/D=σ1/2E x[2-μ]


εh =pd/4tEx[2-μ]

 

Minor principal strain

  ε2=ε longitudinal= δL/L----------i


ε2= 1/E [σ2-μσ1]-------------ii

σ2 = pd/4t = σ1/2

Equating i & ii

 εL=δL/L=σ1/2E x[1-]


εL = pd/4tEx[1-2μ]


Volumetric strain



δV/V=pd/4tEx[5-4μ]

Thickness of the shell



Safe condition of design (σ max⁡)ind ≤(σt )per



σ hoop⁡ ≤(σt )per 

σ hoopcylindrical=pd/2t  ≤ (σt )per

σ hoop⁡ spherical=pd/4t  ≤ (σt )per 

Thin C.P.V

According to failure theory (MPST,MSST)

PD/2t= ≤(σt )per

t PD/2(σt)per+corrosion Added


Thin S.P.V


According to failure theory (MPST,MSST,MDET)

PD/4t= ≤(σt )per

t ≥PD/4(σt)per+corrosion Added

Refer Static Structure Analysis for thin Pressure Vessel in Ansys for better understanding .

Static Structure analysis of Pressure vessel in Ansys 


Wednesday, 5 April 2017

AISC's Structural Steel Shapes

Structural steel design  is an area of knowledge of structural engineering where we used to design steel structures. The structures can range from schools to homes to bridges. Structures such as buildings, bridges, aircraft and ships are all examples which comes under steel structure. 

The effects  cause on structure due to application of load is determine through structural analysis Strength of materials is the branch of engineering which deals with the study of structural design. Engineering software such as STADD Pro, TEKLA , SACS, ANSYS  etc.  are used to analyze their strength. 

Basically  Steel structure is steel construction material with a unique  profile and  a specific shape or cross section with certain standards of chemical composition and mechanical properties.

The American Institute of Steel Construction (AI SC), Inc. publishes the Steel Construction Manual (Steel construction manual, or SCM), which is currently in its 14th edition. Structural engineers use this manual in analyzing, and designing various steel structures.

The mentioned link will give you the complete description of AISC 's structural steel shapes in the US  and will provide you the reference to determine the availability and engineering design data of specific structural steel shapes.

AISC shapes image
Different parameter for different shapes as per AISC standard and  codes

(Click Here) Link:- AISC Structural Shapes

Click above link to find ASIC Structural Shape Properties 





Source:-

https://en.wikipedia.org/wiki
http://www.engineersedge.com

Saturday, 25 March 2017

Shear and Bending Moment diagrams


Shear and Bending Moment diagrams


Bending Moment -

It is reaction produce in a element when an external force or moment is applied to the element which causes elements to bends.

Shear Force - 

force acting parallel to the cross section of elements or acting along the plane is      called a shear force or shearing force.
shear force direction
Below is the Link provided for Shear Force and Bending Moment Diagram Calculation of a Beam:-

Below I am showing how to calculate shear force and bending moment diagram. you can find many link for calculating bending moment diagram for different loading and support. example i          have show  below for one condition.

Be care full about units of input data to get the correct result.

image: loading and  support

shear force and bending moment diagram

shear force and moment calculator

shear and moment diagram



Monday, 20 March 2017

Finite Element Analysis of Composite Sandwich Panel Under Static Load condition

Definition of composite material terminology:-


composite materials:

A Composite material is a material made from two or more constituent materials with different physical or chemical properties .when it is combined it produces a material with characteristics different from the individual components.
composite material example


Orthotropic martial:-

Orthotropic materials have material properties that differ along three mutually-orthogonal twofold axes of rotational symmetry and their properties change when measured from different directions.


Anisotropy:-

 is the property of material which depends on direction, which implies different properties in different directions, opposite to that of  isotropy. It can be defined as a difference, when measured along different axes, in a material's physical or mechanical properties.
anisotropic material example wooden block