MECH419/928 Finite Element Methods in Engineering Assignment 1 Brief - UOW

Assignment Rules (Please read):

1. The assignment may be completed individually or by a group (of maximum 2 members). Members may be from the same or different tutorial groups.
2. The assignment is due in Friday week 8 (2nd May) and submitted as hard-copy report to Prof. Kosasih by the Close of Business hours (5pm) of the 2nd May. Late submission will incur penalty as described in the subject outline. Copying or having someone else /AI software doing the assignment will result in severe penalty with recommendation of zero mark or TF, and possible expulsion from the university. Please seek our advice if you are unsure about the university policies regarding copying (see subject outline under University and Faculty Policies).
3. As this assignment is considered as engineering project undertaken by group of engineers, group synergy and teamwork are part of the learning. So, if the assignment is completed by group, include statement indicating the effort or contribution to the assignment by each member.
4. The MATLAB script files and function files must be included as appendix in the report. Actual files are not needed, but the marker has the right to request them if needed.

As design engineers, your team is responsible for designing lift device shown in Figure 1. Select an appropriate carbon steel material and choose a cross-section shape that maintains a moment of inertia ratio of no more than 4:1 between its two principal directions. You may vary the cross-section dimensions along the arm length to minimize weight.

The actual structure consists of four support arms, but the given loads apply to a single pair. These loads represent operating conditions and should incorporate an appropriate factor of safety for human safety.

When developing finite element models, remove the platform and replace it with statically equivalent loads at joints B and D. Model the arms from B to D, the intermediate connection, and the hydraulic actuator using truss elements.

Task Breakdown

(a) Finite Element Model Development (60 marks)

• Develop a finite element (FE) model of the lifting unit. Carefully select element types based on whether members primarily experience bending or axial stresses.
• Use the model to determine the loader’s deformed shape (nodal displacements) and the stresses in each member (or element).
• Implement the model in MATLAB, either by developing code from scratch or modifying the provided FE MATLAB programs. Compute member deformations and stresses.
• Summarize the selected steel grade and cross-sections.
• Clearly present and interpret results, justifying model assumptions such as element types selections, number of elements, frictionless pin joints, and small-strain behaviour. Include brief theoretical background where relevant.

(b) ANSYS Workbench Analysis (10 marks)

• Perform a similar analysis using ANSYS Workbench.
• Compare the deformation and stress results with those obtained in (a) and provide commentary on the differences.

(c) Professional Engineering Report (30 marks)

• Present findings in a well-structured professional report, including:

• Executive Summary
• Table of Contents
• Clear and logical report structure
• Well-labelled figures with units on axes
• Numerical results with proper units

• Summarize key results, including displacements, stresses, section dimensions, and material specifications.