ansys/workbench mechanical engineering

Project

Note: You can work on this project individually or as a group of two.

Your assignment is to design plastic support, or bracket, to minimize material cost while meeting design specifications 1 and 2 refer to Figure 1. The bracket must be made of one of the plastic materials listed in Table 1.

In this project, do not consider manufacturability issues (you can discuss this in your report) or any other similar concerns related to use of the materials listed in Table 1. As shown in Table 1, pricing may not be realistic for today’s market but assuming the prices are realistic for this project. Only consider the material information provided in Table 1 and the design goals and specifications as outlined in this assignment sheet. All results calculated in this assignment must be based on a 2D plane stress assumption. It is up to you how you choose to do your design work, but your final design must be at least verified with a valid finite element analysis. The finite element analysis must be completed using ANSYS/Workbench. Plastics can experience nonlinear behavior in some circumstances. In this work, however, assume a linear, static analysis is valid.

Referring to the coordinate system in Figure 1, the bracket must have a constant thickness, T, in the z-direction (the “out-of-page” direction). The idea is that the part could be cut from a constantthickness sheet of material that was either extruded or molded. Regardless of how it is manufactured, assume isotropic, elastic material properties. The allowable range for the thickness is 0.20” ≤ 𝑇 ≤ 1.75”. Your design is not required to span the full 8” width for the entire 15” length. It must span the entire 8” width at the top and the bottom and it must all fit within an 8” × 15” rectangular area. It cannot include locations that would produce a stress singularity for which finite element stress result would be invalid. So, sharp internal corners must be avoided. The design must be symmetric about the vertical axis shown. The 2D plane stress model must take advantage of symmetry. So, only half of the geometry is to be modeled.

Mesh the bracket with an adequate mesh for producing accurate results. Perform a linear, static analysis in ANSYS to solve for stresses and deflections. Along the top edge, the bracket is constrained from vertical ( y-direction) deflection, but it is not constrained from x-direction deflection along the top edge (except at the plane of symmetry). Along the bottom edge is a uniformly distributed constant load.

You must arrive at a design that meets the specifications listed below and that you submit a valid finite element model that confirms that your design is acceptable. Minimizing part cost is also essential. Your grade will depend, in part, on the final price per part for your design.

Design Specifications:

1. When a 150 pound uniformly distributed load is applied to the bracket, the factor of safety with regard to stresses must be at least 2.0. The factor of safety can be calculated by dividing the material yield strength by the maximum von Mises stress (Equivalent Stress) in the bracket. The load is applied along the bottom horizontal surface, as shown in Figure1. Note that the total load for the entire structure must equal 150 𝑙𝑏𝑠. In Workbench, the load can be applied as pressure or a force. Be sure your model appropriately makes use of symmetry, and the result of the applied loading in your analysis is consistent with 150 𝑙𝑏𝑠 total loads applied to the entire structure. Since your taking advantage of symmetry, the load applied to the half that you model should be 75 𝑙𝑏𝑠.

2. Under the loading outlined in Item 1 above, the vertical direction ( y-direction) deflection for any point on the bottom edge on which the load is applied cannot exceed 0.015”. Suppose the model is set up according to the coordinate directions shown in Figure 1, based on the loading. In that case, the deflections along the bottom edge will be in the negative y-direction, so the maximum absolute value of the y-direction deflection for any node along the bottom surface must not exceed 0.015”.

Submission Instruction

Submit a document named XXXX-(XXXX)proj1.pdf and an archived copy of your Workbench model for your final design, including the static analysis solution that verified your design. The file should be named XXXX-(XXXX)proj1.wbpz, where “XXXX-(XXXX)” is the first four letters of each group member.

The final report should include the following sections

· Brief Introduction

· Modeling and Optimization procedures

· Results and Discussion

· Conclusion

You may want to include the following items into the above four sections:

1. Material specified.

2. Volume of material per part in units of in3.

3. Material cost per part.

4. Thickness Dimensions, T, in units of inches.

5. Maximum absolute value of y-direction deflection, in inches, along bottom edge.

6. Maximum von Mises stress, in unites of ‘lbs/in2 (or, psi), in the part.

7. Material yield strength, in psi

8. The safety factor with regard to the maximum von Mises stress.

9. A plot of the solid model for your final bracket design.

10. An element plot of your final meshed bracket.

11. A contour plot showing the von Mises stresses throughout your final design. Make sure legend shows indicating stress values in psi.

12. A contour plot showing the vertical direction ( y-direction) deflections. For the deflection plot, the color contours should be related the vertical direction. Make sure the legend shows indicating the y-direction deflection values in inches.

Fonts and Spacing

Fonts should be ‘Times New Roman’ 12 points, and 1.5 line spacing is recommended. The final report should not exceed three pages. You may want to attach all details as an appendix to your report.