Thursday, June 4, 2009

Frequency and Time Responce analysis on Shock Absorber

Frequency Response Analysis Result

Frequency Response Analysis:

              In this analysis we tried to analyze the frequency response analysis of the model with same local measure as in the time response analysis. A vertex point of damper is selected is as the local measure to analyze the behavior of the model. The following figure shows the results obtained from frequency response analysis. The x-axis shows the frequency and y-axis results the displacement. The maximum displacement 0.00020 is obtained at 50Hz frequency. 




Time Response Analysis:

              In order to run time and frequency analyses a local measure has to be created in order to know the behavior of the spring and damper at different displacement and frequency. In this project we selected a vertex point of the damper as the local measure. Local measures obtained in Pro/MECHANICA shows the point where we fixed the local measure in order to analyze the behavior of the model.

              In this attempt we tried to analyze the time response of a model with displacement as a measure. The following figure shows the results obtained with time as x-axis and measure1 (displacement) as y-axis. The main aim of conducting this analysis is to analyze the time response of the model which gives maximum and minimum stress at the local measure. 




Engineering Design of a Shock Absorber Using Finite Element Analysis

             
 
A shock absorber was designed using finite element analysis. The absorber is intended for use as a connecting attachment between chassis and lower arm of a car as a steel column, which will allow load to be carried on a two end holes. The shock absorber was analyzed with FEA, and adaptive analysis was used to ensure accurate results. Two design variables. The diameter of a spring cross section and the upper mount of the Damper, wereconsidered for design. The part was optimized to minimize mass with a limit on allowable stress to prevent yielding of the material in service. A final adaptive analysis was performed to verify that the stress for the optimized shape is accurate.
                                                                Model with Spot-weld
Deformed spot weld comparing with beam

                              Here we assembled two dampers and spring in which they met at non-mated surface, with a Spot weld which used to enforce compatibility at the interface. Here we estimate a small contact region on both the damper and the spring and then use a spot weld between the two contact regions created between damper and spring without doing a detailed analysis. a contact surface is located on the damper and the spring as shown in the following figure and a spot weld  has been created between them.  The figure shows how the local surface area has been created on both the damper and the spring. A spot weld was used to connect the two localized regions. All the material properties have been assigned and a load of 1000lbs has been applied to check the deformation and a static analysis is carried out on the shock absorber. The Damper had been constrained on the other end. Analysis was carried out, Run was completed without any errors and the max stress in the model was 2.137e+03. The deformed shape of the assembly is shown in the figure. The deformed assembly with beam elements is also shown in the figure, the scale was too small to visualize in the picture. Figure shows the comparison between the solid elements of the assembly and beam elements of the assembly.

FEA Analysis oin Vehicle Suspension System








                                  















Finite Element Analysis(FEA) has been carried out on a vehicle suspension system. The mesh was refined to obtain better factor of safety(FOS). Static analysis was carried out using COSMOS analysis tool and the 3D model was created using Solidworks. We can check for part failures by performing analyis at various nodes. Much avanced analysis can be done using cosmos.