Solution:

Conceptual design:

Conceptual Design is an early phase of the design process, in which the broad outlines of function and form of something are articulated. It includes the design of interactions, experiences, processes, and strategies.

The design teams recognize that the vehicles should not be optimized with respect to only one specification, but rather balanced to meet all the requirements.

In an engineering product design environment, concept design or conceptual design is an early stage of a product design process.

Within the new product development cycle, it typically sits between the product planning requirements and embodiment design.

We next follow the thought process of a hypothetical team as it begins to create several design concepts.

The students document their ideas in a bound design notebook, and they use written comments and hand drawings to describe each concept.

First Concept: Compound Geartrain:

As the discussions continue, the team next devises the option shown in Figure, in which a compound geartrain transfers power from the mousetrap to the drive axle.

This vehicle has only three wheels, and a portion of the body has been removed to reduce weight.

The concept incorporates a two-stage geartrain, and its velocity ratio is set by the numbers of teeth on the four gears.

The team’s illustration of a two-stage geartrain is arbitrary; a system with only one stage or more than two stages might be preferable.

However, the students accept such ambiguity, and they realize that a decision for the geartrain’s velocity ratio is not yet necessary.

During the give-and-take of the meetings, the team identifies additional constraints that are common to their first and second concepts.

For instance, the students agree that the vehicle should be designed so that the drive wheels do not spin and slip as the vehicle accelerates.

Otherwise, some portion of the limited energy that is available from the mousetrap’s spring would be wasted.

To prevent slippage, the weight could be added to the vehicle to improve contact between the drive wheels and the ground.

On the other hand, a heavier vehicle would be slower because the potential energy of the mousetrap spring is converted into the vehicle’s kinetic energy.

As they investigate the project in more detail, the students see that the technical issues at hand are interrelated.

Even in the context of this seemingly straightforward exercise, the designers must grapple with competing constraints and requirements.