Wind Load Calculations and Modeling

2018-02-20T12:26:27+00:00

 Part 1 of our Wind Load Series “Wind load” is a calculated value representing the total force on a structure or object cause by pressure from wind moving over it.  In this blog series, we will discuss different methods for wind load calculations, the factors that influence its magnitude, and the effects a high wind load can have on a structure.  Wind load is most commonly addressed by civil and structural engineers when designing buildings, but mechanical engineers can encounter the effect when designing tall objects like cranes, telescoping communications masts or wind turbine towers. Wind Load Essentials As a force, wind load is the product of pressure distributed over an area (psf times ft2 or Pa times m2).  In [...]

Wind Load Calculations and Modeling 2018-02-20T12:26:27+00:00

Window Energy Efficiency: Solar Heat Gain and Visible Transmittance

2018-08-22T11:55:28+00:00

Conduction and Radiation of Thermal Energy In my last blog post, I wrote about the conduction and radiation of thermal energy through windows and the thermal transmittance value, called the U-Factor, that characterizes that heat transfer.  The U-factor is useful in evaluating window performance and making wise decisions when specifying components for a building, but it is only one piece of the puzzle.  The National Fenestration Research Council (NFRC) mandates a second value alongside U-factor in its certification process, called the Solar Heat Gain Coefficient (SHGC).  SHGC represents the ability of a window to resist heat gain from radiation, like the sunlight in Figure 1.  This is obviously a challenge, given that the entire point [...]

Window Energy Efficiency: Solar Heat Gain and Visible Transmittance 2018-08-22T11:55:28+00:00

Window Energy Efficiency: Thermal Transmittance

2018-08-22T11:46:58+00:00

Figure 1: Windows catching sunlight By Magda S [FreeImages.com Content License] In our last blog post, I wrote about the thermal resistance (R-value) and transmittance (U-factor) of insulation and windows.  The R-value represents how well a material prevents heat transfer through its thickness, and U-factor is its inverse, representing how much heat a material will conduct through.  These values are fairly simple to calculate for most building materials materials like the bricks and panels in Figure 1, as they primarily experience only conductive heat transfer.  Windows are a more challenging proposition, however, since the heat transfer through them includes radiation across the entire spectrum, not just the visible light we see and the infrared we feel.  In [...]

Window Energy Efficiency: Thermal Transmittance 2018-08-22T11:46:58+00:00

Energy Efficiency in Building Materials, Insulation and Windows

2018-04-04T09:48:28+00:00

Figure 1: FLIR image of two houses showing energy loss. Colors towards red on the scale indicate warmer surfaces and more energy loss. The basic principle behind thermal insulation is simple to understand.  The harder it is for heat to travel through a material, the better insulator that material will make.  In this blog, I’m going to take a look at how that effectiveness is quantified, after a brief review of the three methods of heat transfer.  The building and construction industry use a ratio called the R-factor to indicate how well a building material can insulate a space.  Also called the thermal insulance or thermal resistance, a higher R-value indicates a more effective insulator. Heat Transfer Methods There are [...]

Energy Efficiency in Building Materials, Insulation and Windows 2018-04-04T09:48:28+00:00

Italian Masters: Leonardo da Vinci – Artist, Engineer, Scientist

2018-02-20T13:14:29+00:00

Figure 1: Leonardo da Vinci, by Francesco Melzi Over the course of this blog series, I have written about a number of Italian Masters of science and engineering, from astronomers like Galileo and Cassini to physicists like Torricelli and Venturi.  I’ve saved the best for last, however: Leonardo da Vinci.  He is the quintessential renaissance man who fits both our running definition of “Italian Master” as well as being included in the standard list of Masters with Rafael, Donatello and Michelangelo  Leonardo’s incredibly broad array of talents and interests have long been the subjects of movies, books, TV shows, and, of late, video games.  Throughout his life, he had one hand in the arts, ranging from painting, sculpting, music, history, and literature, [...]

Italian Masters: Leonardo da Vinci – Artist, Engineer, Scientist 2018-02-20T13:14:29+00:00

Thermal Expansion in a Glass and Aluminum Window: Part 2

2018-02-20T13:29:14+00:00

Figure 1: Simplified model of an aluminum-glass window   In last week’s blog, Thermal Expansion in a Glass and Aluminum Window: Part 1, we introduced the basic concept of thermal expansion in solid materials.  Since CTE mismatch can impose extremely high stress, during mechanical engineering design one must consider the temperature exposure and expansion or contraction of a material.  In order to help the read gain insight, we used a simplified aluminum-framed window to demonstrate that a hot summer day would be enough to shatter glass if the window wasn’t equipped with a flexible gasket between the frame and the glass.  For this entry, we utilize a finite element analysis (FEA) to elucidate the stress effects caused by both high and [...]

Thermal Expansion in a Glass and Aluminum Window: Part 2 2018-02-20T13:29:14+00:00

Italian Masters: Volta Jump-Starts Electrical Engineering

2018-02-21T10:28:40+00:00

Italian Masters: Volta Jump-Starts Electrical EngineeringFigure 1: Girolamo Cardano (1501-1576) Welcome back to our series on Italian Masters of math and science.  Last week I wrote about Galileo’s extensive accomplishments both in the field of astronomy and beyond.  This week, I’ll take a look at another renaissance polymath who dabbled in astronomy, along with his work in mathematics, medicine, biology, chemistry, philosophy, and gambling (yes, seriously): Girolamo Cardano.  Cardano is a less well-known figure than Galileo or some of the other scientists I’ve written about who have famous equations or units of measurement named after them, like Volta or Torricelli.  He is regarded as one of the greatest mathematicians of his age, however, and made a great many contributions to science, [...]

Italian Masters: Volta Jump-Starts Electrical Engineering 2018-02-21T10:28:40+00:00

Thermal Expansion in a Glass and Aluminum Window: Part 1

2018-02-21T10:38:23+00:00

Equipment designers must accommodate thermal expansion (CTE)of dissimilar materials, especially when they are subject to large temperature changes.  This problem is often called "CTE mismatch."  In this blog, we give the fundamentals of thermal expansion calculations used in thermo-mechanical analysis. These calculations are simple but useful, and easy enough to perform by hand or with a spread sheet. For more complicated shapes, one must use computer modeling.  As an example, we perform a finite element analysis (FEA) in a later blog http://glewengineering.com/thermal-expansion-in-a-glass-and-aluminum-window-part-2/, of a glass and aluminum window and frame to show where the stress is excessive.  This points to the obvious need for a gasket to perform as a thermal interface material, in order to lessen [...]

Thermal Expansion in a Glass and Aluminum Window: Part 1 2018-02-21T10:38:23+00:00

Italian Masters: Galileo’s Stellar Science and Engineering

2018-02-21T10:55:17+00:00

Portrait of Galileo Galilei Justus Sustermans [Public domain], via Wikimedia Commons I’d like to return to our previous series on the Italian Masters, focused not on the usual masters or painting and sculpture but on the masters or science, mathematics, and engineering.  So far in the series I’ve written about the accomplishments of Volta, Cassini, Venturi and Torricelli.  Today, I’d like to look at one of the greats: Galileo Galilei.  Galileo is most famous today for standing up for heliocentrism against the Catholic Church and spending the last years of his life under house arrest as punishment.  However, Galileo didn’t let controversies or confinement stop him, and accomplished a great amount of research in not only [...]

Italian Masters: Galileo’s Stellar Science and Engineering 2018-02-21T10:55:17+00:00

12 Years a Martian: Mechanical Engineering on Mars, The Red Planet

2018-04-10T16:24:41+00:00

Figure 1: Mars Exploration Rover mobility testing By NASA

12 Years a Martian: Mechanical Engineering on Mars, The Red Planet 2018-04-10T16:24:41+00:00

Semiconductor Safety: Pyrophoric Gases

2018-02-21T15:25:24+00:00

Fig. 1 Tall Fire from Chemical We have written about pyrophoric materials in a number of Glew Engineering’s previous blogs on safety in semiconductor fabrication, but have yet to cover how to define it or its danger.  At its simplest, a pyrophoric substance is any substance that spontaneously ignites in room temperature air.  As one might imagine, spontaneous combustion on contact with the regular atmosphere we live in can be quite dangerous. Last year, Glew Engineering assisted a research lab in designing a safe gas distribution system for their plasma-enhanced chemical vapor deposition chamber.  During the initial work, the building administrators and safety managers were concerned about the lab’s proposed use of silane and germane, two pyrophoric and toxic materials.  To them, [...]

Semiconductor Safety: Pyrophoric Gases 2018-02-21T15:25:24+00:00

12 Years a Martian: Materials Science on the Red Planet

2017-11-09T10:25:54+00:00

Figure 1: Diagram of the scientific equipment on MER-B Opportunity Mars Exploration Rover Launches Press Kit, June 2003, p. 41 [i] I mentioned in a blog last week that Mars Exploration Rover B (FIgure 1), more affectionately called Opportunity, recently celebrated the 12th anniversary (in Earth years) of its landing on Mars.  12 years without maintenance on the hostile surface of another planet is incredible, considering the original operational time was planned for only 3 months.  Mars Science Laboratory Curiosity currently gets the most press, with its larger tool library and fancier cameras, but there are still scientists and engineers at JPL piloting Opportunity from one scientific site to the next.  In the last blog, I mentioned [...]

12 Years a Martian: Materials Science on the Red Planet 2017-11-09T10:25:54+00:00

FEA Consulting Part 6: Analyzing Results

2017-11-08T16:44:21+00:00

Figure 1: Shear stress results for our concrete slab simulation.  The red area of high compression is where the corner of the square-shaped supporting column holds up the slab. © Glew Engineering Consulting, 2016 Welcome to the final entry in our finite element analysis (FEA) blog series, in which I'll discuss a little about analyzing and evaluating FEA results.  Over the course of this blog series, I've covered tips on setting up the model in CAD and in the FEA program, configuring the analysis, and generating results.  The final step in the process is the analysis of the results, both to get the answers to whatever problem inspired the FEA simulation and to ensure that the final results are [...]

FEA Consulting Part 6: Analyzing Results 2017-11-08T16:44:21+00:00

12 Years a Martian: Engineering Challenges on the Red Planet

2018-08-29T12:57:38+00:00

Figure 1: Mars Exploration Rover By NASA/JPL/Cornell University, Maas Digital LLC [Public domain], via Wikimedia Commons Depending on which Facebook pages or Twitter feeds you follow, some of you may have caught wind that Opportunity (Mars Exploration Rover B, Figure 1) recently passed its twelfth anniversary of its landing on the red planet.  Opportunity’s ongoing trek across Mars represents a fantastic accomplishment in engineering.  At the time I’m writing this, the rover has been in continual operation for over 4,300 Earth days (that’s about 4,185 Sols, or Martian days).  Considering its original planned mission time of 92 Earth days, Opportunity has exceeded its design lifetime by 4,700%.  Imagine having a car that, instead of a [...]

12 Years a Martian: Engineering Challenges on the Red Planet 2018-08-29T12:57:38+00:00

FEA Consulting Part 5: Generating Results

2017-05-03T15:37:10+00:00

Figure 1: Displacement results for our concrete slab simulation.  The slab is supported in the center by a square column, and on the sides by a theoretical wall. © Glew Engineering Consulting, 2016 Time now for the last in our blog series on FEA.  I’ve previously discussed how to set up CAD for FEA, how to mesh that CAD model and the different types of analysis that FEA programs can run.  The next step in the process is generating results from the FEA simulation, like the displacement illustration in Figure 1.  These are fantastic tools for generating useful reports, and are also very useful in helping an FEA consultant or engineer check the accuracy of the own results. As a [...]

FEA Consulting Part 5: Generating Results 2017-05-03T15:37:10+00:00

FEA Consulting Part 4: Simulation and Analysis

2017-05-05T10:07:54+00:00

Figure 1: Mesh, loads and constraints, ready for analysis © Glew Engineering Consulting, inc. 2016 Welcome again to our series on finite element analysis (FEA).  In the last blogs, I covered steps on setting up a computer-aided design (CAD) model and how to set up the mesh and boundary conditions, the most crucial steps in FEA simulation.  In this blog, I’ll look at the actual simulation and analysis, which can be the most time-consuming stage in the process. As a reminder, for an example I’ve been using a recent project we worked on involving punching shear in reinforced concrete.  We were examining the effectiveness of reinforcing a column-supported concrete slab against the possibility of that column punching through the concrete. Types of [...]

FEA Consulting Part 4: Simulation and Analysis 2017-05-05T10:07:54+00:00

Italian Masters: Cassini – Expert Engineer and Astronomer

2017-05-03T14:34:35+00:00

Figure 1: Giovanni Domenico Cassini We’ve been taking a break from hard-hitting mechanical engineering and materials science blogs with some pieces on the Italian masters of science, mathematics and engineering in the 16-19th centuries.  In previous blogs, I explored the lives and contributions of mathematician/physicist Evangelista Torricelli and physicist/engineer Giovanni Venturi.  For this blog, I'm focusing on Giovanni Domenico Cassini (Figure 1), a structural engineer and astronomer extraordinaire in the late 17th century.  Cassini started small, studying astrology (not astronomy!) early on in his career, but his fascination with the actual scientific properties of our celestial neighbors and his lifelong dedication to watching the night sky led him to a number of great discoveries. Giovanni Domenico Cassini (1625-1712) Giovanni Domenico Cassini [...]

Italian Masters: Cassini – Expert Engineer and Astronomer 2017-05-03T14:34:35+00:00

FEA Consulting Part 3: Meshing and Boundary Conditions

2018-03-27T15:27:13+00:00

We'll continue on now with our blog series on finite element analysis (FEA).  After discussing how to best set up a computer-aided design (CAD) model for FEA simulation, in this blog I'll cover the next step: meshing the model and applying boundary conditions.  "Meshing" is the process by which the CAD model is separated into discrete finite elements; it can be done in the same program that runs the FEA numerical simulation later, or it might be performed in a standalone program, depending on your software.  Boundary conditions are the loads (forces, movements, impacts, etc) and constraints that interact to actually cause deformation and stress in each element, and in turn the model as a whole. Mesh Generation The mesh essentially [...]

FEA Consulting Part 3: Meshing and Boundary Conditions 2018-03-27T15:27:13+00:00

Italian Masters: Venturi and the Venturi Effect

2017-05-03T14:48:59+00:00

Figure 1: Giovanni Battista Venturi [i] Glew's News is doing a short series highlighting the lives and accomplishments of the Italian Masters of science, engineering, and mathematics.  In the last blog, I wrote about Evangelista Torricelli, a mathematician and physicist from the 17th century.  In this blog, I'm focusing on Giovanni Venturi (Figure 1), an accomplished physicist, hydrodynamicist and engineer. Giovanni Battista Venturi (1746-1822) Giovanni Venturi was born to a wealthy family in Reggio, Italy in 1746.  A talented young student, by the age of 23 the local seminary had already ordained him as a priest and professor.  His talents in mathematics didn’t long escape notice at the nearby University of Modena, which appointed him as a professor of geometry and [...]

Italian Masters: Venturi and the Venturi Effect 2017-05-03T14:48:59+00:00

FEA Consulting Part 2: CAD Model Preparation

2017-05-02T16:56:01+00:00

Figure 1: Reinforced concrete mesh © Glew Engineering Consulting Welcome back to our blog series on FEA.  In the last blog entry, we introduced some of the fundamental concepts in finite element analysis (FEA).  This entry in the blog series focuses on the initial steps in preparing a computer-aided design (CAD) model ready for use in an FEA program.  Since FEA programs are very sensitive to the data they have to work with, it's important that the CAD models being analyzed are compatible with the analysis methods the FEA program uses. In order to illustrate my points throughout the blog series, I will introduce a recent FEA consulting project that we completed. Modeling Punching Shear in a Concrete Slab We were recently approached by an academic, who was examining [...]

FEA Consulting Part 2: CAD Model Preparation 2017-05-02T16:56:01+00:00