Screw Jack CAE BenchmarkCAE analysis for Screw Jack

Content Case 1: Jack resting on horizontal plane jack opened at 325.5 mm. Case 2: Jack resting on inclined plane with angle of inclination + 5 degrees Case 3: Jack resting on inclined plane with angle of inclination + 8 degrees

Overview of the model used

Assumptions FEM technique is used with NX Nastran solver for solving static solution. Material is assumed to be homogeneous and isotropic and UTS data is used

as provided by customer i.e. 28 Kg/mm^2 (275 N/mm^2) Screw Jack model is used as provided by client. Results may vary depending

on the accuracy of the model. 3D Tetrahedral mesh is used for connections 1D elements are defined.

Case 1: Jack resting on horizontal plane jack opened at 325.5 mm Jack is resting on horizontal plane with height of 325.5 mm and dead load of

450 Kg is applied at the top. Displacement and the stresses are recorded.

Boundary ConditionsLoad= 450 Kg

Fixed support(Base)

Case 1: Displacement Results

Maximum Displacement = 0.427 mm

Case 1: Elementral stress (Von-Mises)

Maximum Stress= 192.92 N/mm2FOS = 1.42

Case 1: Elementral stress (Von-Mises)Maximum Stress= 192 N/mm2

Case 2: Jack resting on inclined plane with angle of inclination + 5 degrees. The problem is resolved by applying a load inclined at an angle of 75 degrees

positive ( i.e. 90-5= 85 degrees) Displacement and the stresses induced are recorded.

Boundary Conditions Load 450 KgInclined at +85⁰

Fixed support

Case 2: Displacement ResultsMaximum Displacement = 0.696mm

Case 2: Elemental Stress (Von-Mises)

Maximum Stress = 339.20 N/mm2 FOS= 0.81

Case 2: Elemental Stress Failure Area

Case 3: Jack resting on inclined plane with angle of inclination +8 degrees

Boundary ConditionsInclined load 450 Kg at 82⁰

Fixed support

The problem is solved by applying a load inclined at an angle of 75 degrees positive ( i.e. 90-8= 82 degrees)

Displacement and the stresses induced are recorded.

Case 3: Displacement Results

Maximum Displacement = 1.101 mm

Case 3: Elemental Stress (Von-Mises)

Maximum stress = 492.45 N/mm2 FOS= 0.55

Case 3: Elemental Stress Failure Area

Results & Discussions The CASE 1 is safe and there is no failure occurring in it. It is advised to modify and optimise the base part for stress as the part is

showing failure due to crushing in case of inclined load application (case2 & case 3 )