Finite Element Analysis of Hydraulic Actuator by using CAE tools

A hydraulic system is a fluid power system that is commonly used in industries due to its ability to sustain high pressure .So, here in this paper double acting hydraulic actuator is designed based on the force acting on it and the stroke length .Analysis of different parts of actuators is done by using CAE tools checking for the equivalent stresses and deformation. Two different materials are also used to check proper material to be used. Keywords--Hydraulic ,actuator ,double acting ,analysis


I.
INTRODUCTION: Hydraulic actuators are the end results of Pascal's law. Hydraulic actuator is the device which converts hydraulic energy into mechanical energy it consists of cylinder that transforms the flow of pressurized fluid into a push or pull of piston rod .In double acting actuators the fluid pressure can be exerted from both sides. Hydraulic actuators are rugged and suited for high force applications.

II.
METHDOLOGY: The load of 21832 N is to be sustained by actuator but if fails suddenly ,so taking into account sudden loading conditions it should be designed for 43664 N ( 21832 * 2).So by using CATIA V5 models are made, and every component is analyzed separately using two different materials that are low carbon steel and E335 steel. Low carbon steel is used as it is lighter in weight with good yield strength, tensile strength, corrosion resistance, ductility whereas E335 steel is practically used in industries as a material. So here we find out which one is better.

III. DESIGN PROCEDURE
The following assumptions were taken into the consideration of the design of the cylinder, piston, piston rod and seals in the hydraulic cylinder.

A. Design of piston rod
The rod is more likely to fail by buckling under the compressive load. In this case, the rod behaves like a column and is subjected to buckling. Therefore Euler's formula in the equation below for long column can be used to obtain the piston rod diameter P=π 2 EI/L 2 K 2 Where: P = Buckling load (N) L = the column length (m) I = Moment of inertia (m 4 ) E = Young's Modulus of Elasticity for the column material (Pa) K = the end fixing factor =0.7 E = Young's modulus of the material used in this design calculation is 120 GPa P = cylinder force * factor of safety = 43664 * 3 = 130992N 130992 = (π 2 *210*10 9 *I)/(1.135 2 *0.7 2 ) I=39.894*10 -9 m 4 Π*d 4 /4 =39.894*10 -9 d=15 mm from Baym Hydraulics Corporation catalog of metric rod wipers and piston seals the nearest standard rod seal diameter is 20 mm.

B. Design of the piston
Let A be the full area of the piston and a be the cross sectional area of the piston rod. Since the design is a double acting double ended hydraulic cylinder, pressure is acts on both sides of the rod, hence the area which the pressure is acting on is given by (A-a). The force produced is given in the equation below.

V.CONCLUSION
Here, design and analysis of different parts of actuator i.e, piston rod, piston ,cylinder is done using CATIA V5 and ANSYS . From the above obtained value , we can conclude that the stresses developed in low carbon steel are more than E355 steel and the total deformation of E355 is more than low carbon steel. Hence from obtained data it is beneficial to use E355 steel. VI.