The Engineers Tool Box

Here’s a look at a little known analysis software package that strives to bridge the gap between reference materials and high-end applications. 

In today’s world, multidisciplinary expertise is required to solve engineering problems. For example, to determine what caused a failure in a device or a piece of equipment, an engineer must understand the load generation mechanism. These loads can be generated by many variables, including fluid flow, heat, material fatigue, stress, and strain. And to accurately estimate the loading in such failures, an understanding of the behavior of these variables is required. An engineer might need to know how stresses lead to physical breakage or how thermal characteristics caused an electronic circuit to melt.

To solve such problems the engineer is often required to perform calculations involving fluid flow, heat transfer, solid mechanics, dynamics, fatigue, and fracture mechanics. And the challenge is similar during the initial design phase of a device or when evaluating a product or piece of equipment.

The analysis techniques available to design and analysis engineers are quite varied. At one end of the spectrum are detailed analysis computational tools like computational fluid dynamics (CFD) and finite element analysis (FEA); at the other are the hand-held calculator and reference books. In between is a large gap in the levels of complexity, detail, and rigor associated with the tools. The mid region of the spectrum is sparsely populated with in-house software, special purpose calculations, and personal preference calculation spreadsheets. These mid-level tools are not generally available or accessible to the engineer. A spread-sheet calculation created by one engineer usually isn’t shared with other engineers, even within the same organization. And even when they are shared, these calculators are not user-friendly and include little or no documentation.

The analysis spectrum. .

At the other end of the spectrum, very often, simplified calculations based on first principles or correlations are applied to estimate the expected behavior of a device. These calculations also serve to eliminate the possibility of user error during the application of complex tools like CFD and FEA). At times, it is essential to carry out simplified calculations prior to performing a detailed CFD or FEA analysis. For the simplified calculations the engineer uses a hand calculator, reference books, and at times spreadsheet calculators. In these cases, an appreciable amount of time is spent in sifting through reference material the engineer knows about and has access to, and in checking calculations.

Another thing to think about at this extreme is the fact that, once performed, calculations are typically stored in notebooks. Also, the underlying principles and methods used in the calculations are rarely, if ever, captured, which means the repeatability of the calculations is not assured when performed by another engineer. The calculations cannot be easily communicated or repeated, and the lack of semi-automated tools for simple calculations drives engineers to use high-end computational tools for simple problems. It’s like using a sledgehammer to drive a brad through quarter-inch molding.

If an engineer can use an efficient and accurate method for evaluating the design of a product before getting too far down the iteration road, time and money will be saved in getting the new device to market.

There is a clear need to bridge the gulf between the tools at the two ends of our analysis spectrum. Semi-automated tools that can perform a range of analysis calculations varying from the simple to the moderately complex are the answer. An intuitive software package called the EngineersToolbox (ETBX) enables the engineer to interactively explore solutions to typical engineering systems and scenarios and serves to help bridge the void (see Figure 1). ETBX, which was launched as a Web-based tool in 2001, is a product of Engrasp Inc. of Arlington, TX, and includes integrated computational modules designed to rapidly solve typical engineering systems and scenarios.

It bridges the gap between complex analysis packages and simplified solutions by using first-principles, empirical correlations, experimental data, rules-of-thumb, and numerical solutions of conservation equations such as energy, mass, and momentum equations. Now a PC-based tool, ETBX is a comprehensive tool for engineering design, analysis, and reference that eliminates the need to sift through texts and delivers a foolproof method of performing quick calculations. The software captures years of experience and expertise from various sources, captures underlying methods, and is easy to use; repeatability and documentation are assured.

The role of ETBX in the product development cycle bridges the gap betweeh high-end and low-end tools. Click the image to enlarge.

The current version of ETBX covers a comprehensive range of engineering specialties, including solid mechanics, dynamics and controls, fatigue and fracture mechanics, fluid mechanics, heat transfer, numerical methods, and engineering reference utilities. It’s a knowledge vault that would take years of practice and experience to otherwise collect, and ETBX delivers this expertise and body of knowledge in an easy-to-use format to the engineers desk. ETBX solution types include static deflection and stress calculations, natural frequencies and mode shapes, dynamics of linear and nonlinear systems, transient, frequency response, flow rate, pressure drop, and heat transfer computations.

For example, consider the design of an automobile structural component as carried out using ETBX. The load-bearing member consists of an open-section bar. ETBX is used to examine the structural behavior of various bar cross-sections as depicted in Figure 3. The static deflections under prescribed loads are rapidly computed for various cross-sections and sizes as depicted in Figure 4. This allows rapid optimization of the bar shape and size.

Figure 3A. Click images to enlarge.

3B: Automobile structural bar cross-section selection in ETBX.

Static deflection, slope, and shear distribution in bars under static load.

Solutions computed in ETBX modules can be easily transferred and data exchanged between modules, and online documentation provides a comprehensive description of the solution methods. The results can be exported to various formats and its dynamic visualization capabilities can be applied to animate and view deformations in the system.
ETBX has been widely applied in such industries as the automotive, aerospace, chemical, oil and gas, and biomedical fields for design and evaluation of devices, equipment, and components. It has been used to assess the remaining life of products using fundamental calculation methods and to obtain estimates of expected behavior by modeling complex systems using simplified theory and correlations. Ultimately, users have found it helps reduce costs and development time while improving product quality and delivering new designs faster.