Delta Design Exercise
Introduction
Congratulations! You are now a member of an expert design team. Your
collective task will be to design a new medical clinic suitable for
inhabitants of the imaginary Deltoid plane. These written materials,
provided to help you prepare for this task, are organized in four
sections. The next section provides an overview of life on the
Deltoid plane, DeltaP as it is known to the natives. The following
section describes your team, and your design task. A second handout,
different for each team member, provides the specific information you
will need to perform the role you have been assigned within your
team. You will receive this handout at the tutorial you attend later
this week. Each team member will contribute different expertise to the
project, and each has different design responsibilities to
fulfill. All must work together for your team to create a first-rate
design.
Life on the Delta Plane
Life on the Delta Plane is quite different from what you have grown
accustomed to here on Earth. First off, DeltaP is a plane, not a
planet, so your team will be designing in two-dimensional rather than
three-dimensional space. If your design "meets spec" and is considered
attractive and functional by your Deltan clients, one view on a single
sheet of paper, such as the example shown in Figure 1, will convey all
the necessary information to those responsible for constructing the
clinic.
Figure 1
Sample DeltaP Building Plan
The view on this single sheet may not be quite what you expect,
however, because in addition to lacking a z axis, Deltoid space has
unfamiliar relations between the x and y axes as well. What we think
of as "perpendicular" is hopelessly skewed to a Deltan, and
vice-versa. In our units, a right angle on DeltaP measures 60° or
/3 radians. Thus all sides of an equilateral
triangle form lines considered perpendicular to all others. If there
were such a thing as a "circle" on DeltaP, it would be composed of
only 4/3 radians.
But there is no such thing as a "circle" on DeltaP, nor even the
concept of continuity embodied therein. In this flat though angular
world, residents construct their artifacts strictly with discrete
triangular forms. Of these, the equilateral triangle -- with its three
perpendicular sides (!)-- is considered the most
pleasing. Accordingly, your team will design the clinic by assembling
into a cluster the most prized building materials on DeltaP,
equilateral triangular components called "deltas", shown in Figure 2.
Deltas come in red and blue versions and always measure 2 lyns per
side. Four "quarter-deltas", QDs, triangular units of area measure
with sides of 1 lyn, fit within a delta.
Figure 2
DeltaP Building Units
Lyns? QDs? Not surprisingly, Deltan systems of measurement are as
unfamiliar as that for spatial coordinates. Table 1 summarizes the
measurement schemes on DeltaP that you will need to know to carry out
your design task.
Table 1
Measurements on DeltaP
| Measurement | Units | Symbol |
| Time | Wex | wx |
| Distance | Lyn | ln |
| Area | Quarter-Delta | qd |
| Heat | Deltan Thermal Unit | DTU |
| Temperture | Degrees Nin | °Nn |
| Force | Din | Dn |
| Moment | Lyn-Din | LD |
| Currency | Zwig | ! |
All of DeltaP's units of measure share the divisibility and
extensibility conventions of the metric system; in the measure of
time, for example, there are both microwex (µwx) and megawex (Mwx).
In relation to the attention-and life-spans of Deltans, these units
are roughly equivalent to seconds and years, respectively, here on
Earth.
As building components, deltas have functional and aesthetic
characteristics that are more complex than their simple form and even
dimensions would suggest. Especially when assembled into a cluster, as
you will be doing, they behave in interesting ways. Deltas conduct
heat among themselves, radiate heat to outer space, melt if too hot,
and grow if too cool. Red deltas produce heat. All deltas are subject
to DeltaP's two-dimensional gravity (which is itself subject to axial
shifts during DeltaP's not-infrequent gravity waves). Three different
kinds of cement are needed to join them together, and joint alignment
with respect to gravity affects ease of production as well as
structural integrity. Different colors and different quantities of
deltas cost different amounts of money per delta, and can be assembled
in clusters that are either exceedingly ugly or very attractive to
the Deltans. Your task will be to create a design that meets
prescribed goals for all of these characteristics.
Design Team Roles and Responsibilities
Your design team is organized such that each of you will be
responsible for a subset of the design goals. Some of you will be
PROJECT MANAGERS. Your main concerns will be with cost and schedule,
the interpretation and reconciliation of performance specifications,
and negotiations with the contractor and client. You want to keep
costs and time-to-build at a minimum, but not at the expense of
quality. When your team submits its final design, the project manager
must report the estimated cost (in zwigs) and the time (in wex) that
it will take to build.
Others of you will be the STRUCTURAL ENGINEERS. Your main concern will
be to see that the design "holds together" as a physical structure
under prescribed loading conditions. You must see to it that the two
points at which your structure is tied to ground are appropriately
chosen and that continuity of the structure is maintained. When your
team submits its final design, the structural engineer must attest to
its integrity by identifying the strongest and weakest joints, and
estimating the average load on all joints expressed as a percentage
of the failure load.
Others of you will be the THERMAL ENGINEERS. You will want to ensure
that the design meets the "comfort-zone" conditions specified in terms
of an average temperature. You must also ensure that the temperature
of all individual deltas stays within certain bounds. When your team
submits its final design, the thermal engineer must estimate internal
temperature and identify the hottest and coldest deltas.
Finally, one of you will be the ARCHITECT. Your concern is with both
the form of the design in and of itself and how it stands in its
setting. You must see to it that the interior of the clinic takes an
appropriate form and that egress is convenient. You should also
develop a design with character. When your team submits its final
design, the architect should be prepared to discuss generally how and
why the Deltans will find the clinic attractive and functional. The
architect will also be asked to estimate a few more quantitative
measures of architectural performance.
The following section describes the specifications that your design
must meet to be accepted by your clients on DeltaP. Familiarize
yourself with these specifications. Then, for schooling in your
specialty, you will attend a tutorial to be trained in the science and
technology of your domain. The information found there includes the
knowledge and heuristics you will need to estimate the design
parameters for which you are responsible.You should be expert in your
role before your team begins the design phase.
The Design Task
Your Deltan clients have cleared the space shown on the site map
and come to your team with their need for the design of a new
clinic. The cluster itself must meet the following specifications.
The client wants the cluster to provide a minimum interior area of 100
QDs (Each diamond on your girded site map defines an area of two
QDs). The shape of this space, which can of course exceed the minimum,
is a matter of design. The client has expressed enthusiasm for the
newer mode of segmenting interior space, to allow patient privacy
during examinations and testing procedures. This mode breaks with the
two-equal-zone tradition and values the suggested privacy of nooks and
crannies. Still the space must be connected (i.e. no interior walls
can cut the space into completely separate spaces) to allow access to
all rooms by emergency medical vehicles. There must be one and only
one entrance/exit.
Patients are known to be color sensitive to blue; too much blue brings
on the blues, so to speak, and may cause patients to become
depressed. No more than 60% blue ought to be allowed; certainly blue
deltas are not to exceed 70% of the cluster.
The clinic, as all clusters, must be anchored at two points and two
points only. There is a limit to the amount of force each anchor can
support, as well as to the amount of internal moment each joint can
withstand. Exceeding either limit would cause catastrophic failure and
send the unwary residents tumbling into the void. The cluster should
be designed for a life of thirty megawex. Gravity waves, rare but
always possible, should be considered.
The average interior temperature must be kept within the Deltan
comfort zone, which lies between 55 and 65 °Nin. The temperature
of the elements themselves must be kept above the growth point of 20
°Nn and below the melt-down point of 85 °Nn. Delta
temperatures outside of this range will result in catastrophic
structural failure with little more warning than excessive load.
Table 2
Summary of Design Specifications
| Functional Interior Area | 100qd |
| Maximum Cool Deltas (% Total) | 60-70% |
| Average Internal Temperature Range | 55-65°Nn |
| Individual Delta Temperature Range | 20-85$#176Nn |
| Maximum Load at Anchor Points | 20 Dn |
| Maximum Internal Moment | 40 LD |
| Overhead Factor (K) | 1.2 |
| Total Budget | !1400.00 |
All of this -- design, fabrication and construction -- must be done
under a fixed budget and within a given time period. At your team
meeting you are to develop a conceptual design that meets or exceeds
all design goals. When each team submits their design, individual
members will be asked to report design performance on parameters for
which they are responsible.
Copyright 1991 MIT, All Rights Reserved
Authored by Louis L. Bucciarelli and ammended by Amy Smith, MIT, 10
February, 1997, for use in SP 753, Designs for Developing Countries.
This page is maintained by Amy Smith,
mmadinot@mit.edu