# Engineering

## Using K-Factor for Sheet Metal Flat Blanks

The K-Factor method is a versatile way of calculating sheet metal flat blank dimensions.  MEboost employs the K-factor method to calculate flat blanks in two directions.  Consider the flat blank below.  We have already designed the formed part and need to know the overall dimensions as well as the location of the bend lines. Calculating …

## Using Mohr’s Circle for Plane Stress

Mohr’s circle for plane stress shows the relationship between the state of stress, principal stresses, and maximum shear stress.  This article will cover the basics of Mohr’s circle in plane stress, and how it is easily created using MEboost. MEboost also handles bodies under plane strain.  To learn about this scenario, refer to the article …

## An Example of Probabilistic Design

Traditional engineering design employs the concept of a safety factor to prevent failure.  In this article we are going to discuss, with a simple example, how probabilistic design can be used as an alternative to safety factors. Background on Safety Factors In engineering design, uncertainties in material strength, material dimensions, and loading is often accounted …

## Tolerance Analysis Methods

Tolerance analysis is an important part of mechanical design.  It has an impact on cost, performance, and quality which requires a requisite amount of study to ensure tolerances result in a successful design that can be effectively manufactured.  In this article we will look at tolerance analysis methods, and their pros and cons.  We will …

## Decision Making Under Risk and Uncertainty

Decision making under risk and uncertainty is a fact of life.  There are many ways of handling unknowns when making a decision.  We will try to enumerate the most common methods used to get information prior to decision making under risk and uncertainty.  We’ll also look at decision rules used to make the final choice.  For …

## Anecdotal Evidence for the Use of Concurrent Engineering

Concurrent engineering is the practice of including manufacturing, purchasing, service and any other personnel outside of the design team in a project.  The so-called non-designers bring their unique perspective to the project in order to make it more usable, manufacture-able, source-able  serviceable, etc.  Of course the term non-designer is not true.  Anyone with input to the project …

## Evaluating an R&D Project with a Decision Tree

Decision trees are useful for projects that proceed in stages where investment decisions may change over time.  In this application brief, we will use decision tree analysis to evaluate a research and development project where we are uncertain if a commercial product can be produced as a result of the research portion of the project. …

## A List of Questions to Ask When Writing Requirements

Generating a good set of system requirements involves asking a lot of questions.  What follows is a list of requirements questions to help spur the discussion.  Questioning may take the form of interviewing stakeholders, using questionnaires, or asking questions to yourself. The list of requirements questions below can be used as a framework to develop …

## Using Part Symmetry, or Lack Thereof, to Your Advantage

When designing parts for assembly, part symmetry, or lack of symmetry, can be an important factor to consider.  In this article we look at when it’s appropriate to add part symmetry, and when asymmetry is a better option. Symmetrical Parts Designing symmetrical parts, weldments, and sub-assemblies can provide advantages such as reduction of unique parts, …

## Unique Part Number Reduction for the Enterprise

Unique part number reduction across the enterprise can provide numerous benefits.  While it’s desirable to reduce the part count in a given product, what we are focusing on in this article is reducing the unique part numbers in the ERP system across all product lines. For our purposes here, the terms part number or part …