mechanical engineering代写-ME 465代写

ME 465

Homework Assignment 3

Developing Standard Form Optimization Problem Statements

mechanical engineering代写 If the variable bounds or constraint limits are not given, either use defined parameters or reasonable numbers based on logic.

Two engineering problem summaries are provided below. mechanical engineering代写

For each problem, identify the Objective(s), Constraint(s) and Design Variable(s). For the Design Variables, be sure to specify the type (continuous, discrete, dependent, etc.) and provide any specifications that would be required to define these variables (bounds, sets, formulae, etc.). For Constraints, be sure to include the upper or lower limit.

Here is an example of the form we are looking for. This example is not related to the problems below.

Objective:

minimize the total mass

Constraints:

von‐mises stress in region 2 near joint 4 ≤ 200 MPa mechanical engineering代写

displacement at point B ≤ 5 mm

Design Variables:

10 mm ≤ Radius ≤ 20 mm(continuous)

material type: (steel, aluminum, magnesium) (discrete)

If the variable bounds or constraint limits are not given, either use defined parameters or reasonable numbers based on logic.

Be sure to include the pledge on the assignment.

Problem 1: mechanical engineering代写

A popular truck chassis design is to be modified to meet the needs of several new markets.Because these new markets have different and conflicting requirements, it is desired to explore the trade‐off between increasing torsional stiffness and reducing mass. Further, the lowest natural frequency of the structure must be greater than 30 Hz, and the bending stiffness must exceed that of the current design. The gage thickness of four different steel sections can be changed, but only three choices of material thickness are available. The position of cross member 1 and cross member 2 can be modified along the longitudinal direction of the chassis.

Define the optimization statement. Include all detail needed to define the objective(s),constraint(s) and variable(s) in an optimization software package.

Problem 2: mechanical engineering代写

A heat exchanger must be designed to reduce the temperature of computer chips, as shown in the figures below. The design concept is to force a gas (ethylene glycol) to flow over and around some heat fins that are attached to a plate adjacent to the chip. The heat will flow from the chip to the heat fins via conduction, and then will be transferred to the gas via convection. The heat fins must be designed to keep the temperature on the chip surface below a critical value at all times. mechanical engineering代写

Reducing energy usage is of primary concern, and the key energy cost is associated with the flow resistance (pressure drop) when the gas flows around the heat fins. For ease of manufacturing, all of the fins will have the same geometry. But the number of fins and their spacing can be varied. The fin height, base diameter and top diameter can change within specified limits. The material of the fins can also be varied, but there are only three acceptable materials to select from. Define the optimization problem. Include all detail needed to define the objective(s), constraint(s) and variable(s) in an optimization software package.