Objectives
In this assignment you will be required to apply the skills you have learned in the classes in the areas of preparing CAD geometry for FEA, element selection, meshing and mesh optimisation as well as model simplification. This is an individual assignment.
This assessment task aims to introduce students to FEA and its application in CAE. You will be required to numerically analyse the structural performance of a simple structure. You will follow a logical CAE analysis process by starting with a highly simplified model and verifying the results with simple hand calculations. You will then be required to increase the geometric complexity of your model and identify the model set up that leads to sufficient model accuracy combined with the lowest calculation time.
Completing these tasks will require extensive modelling work but the time frame for the project is tight. Your role in this project is to develop numerical models that combine sufficient model accuracy with the lowest possible calculation time to allow the project to be completed in time and successfully.
Introduction and Design Requirements
You have been employed by Cranes'R'Us to assess the structural integrity of an initial design of a slewing jib crane (Figure 1). The crane is manufactured from a structural steel grade (provided in the ANSYS Material Library) and the material data is supplied in Table 1.
The crane should be designed to allow for a load up to 6 tonnes (~60,000 N) and a maximum deflection of 15 mm when loaded at its maximum span. The stresses on the crane must not surpass the material yield stress (use a safety factor of 2).
Project Tasks
The project is broken down into key tasks:
1. Preliminary assessment of the structural integrity of the crane by using an idealised beam element model: assess whether the current design meets the compliance (deflection) and maximum stress criteria.
2. Validate your initial beam model with simple hand calculations to ensure your FEA model is accurate.
3. Provide some design recommendations to the client. You do not need to make or analyse any design changes at this stage, but you should comment on where design improvements could be made based on the results from your analysis.
4. Establish a more detailed, yet still efficient, FEA shell-based model of the design provided to you by the client (Slewing_Jib_Crane.x_t). To complete this you will need to:
a. simplify/de-feature the geometry in order to establish a shell-based FE model;
b. apply the appropriate FE meshing techniques to ensure an accurate yet computationally efficient solution (you will be assessed on the quality of your mesh);
c. assess mesh convergence of your models;
d. assess the structural feasibility of the design;
e. justify and discuss all the modelling decisions you have made.
5. Compile a concise and comprehensive technical CAE report for the client using the reporting template provided (template.docx).
- Do not exceed the table sizing for each section. You must be concise and dot-points are encouraged.
- You must describe both FEA model setups and your findings with regard to the design feasibility.
- Give a justification for all design simplifications you made and show how you established a converged, accurate and efficient FE model.
Design Specifications:
- Load: 6 tonne (~60,000 N)
- Height: approx. 5 m
- Span: approx. 5 m
Compliance Criteria:
- Deflection at max span < 15 mm
- Max Stress - FOS approx. 2.
- Reduced mass and material usage
Attachment:- Crane.rar