The attached spreadsheet contains a simple drop down box to select a material type and from that selection a Lookup function is used to obtain the corresponding material property for that type. The problem with it is that it works for all the materials except the last one listed, ie. material...
I have two columns of data which, via a command button and a macro to perform some calculations, the values change. When I plot these values I want the viewer to see the graph alter as the data changes. In the spreadsheet I see the data in the columns change but the graph just freezes, until the...
In bolting a bracket to a rough forging it's been advised that the surface be machined to present a 'flat' surface. Most of the load is in shear and so the friction is important. In my view frictional forces are independent of the contact area and so the surface finish isn't that important as...
Engineering suffers from an image problem. People believe that engineers simply fix things, but we don't: we invent things. Unfortunately the false image is propagated by hundreds of companies out there who term repair-persons and equipment installers 'Engineers'. Engineering suffers from a lack...
I'm creating an Abaqus input deck using visual basic 6.0 where temperatures are read from an external text file and a .inp file is output with all nodes and elements predefined. In the example I am testing there are over 200,000 nodes but the program crashes with an error saying end of file when...
I have about 8 pairs of x,y data I want to fit a trendline to. The options available though are only for linear, polynomial, exponential, and moving average. The power and logarithmic options are greyed out. Why should that be?
corus
I'm trying to find the pressure which would cause a vessel to fail from a sudden increase in pressure, say by an explosion. Would an impact factor apply, and what value would be appropriate?
corus
I have a series of data points with XY co-ordinates listed in 2 columns. These data points are connected by lines to form a network, but unsequential, ie. data point 1 is connected to point 3, point 2 is connected to 5 etc. The network connections are listed in seperate columns so that the full...
A vessel is lined with refractory which expands and exerts a pressure on the outer shell. As this pressure is caused by thermal expansion of the lining, and as such is self limiting, is the stress in the shell classed as secondary, or as the stress is due to an external force from the refractory...
This is a slant on the familiar problem of the interference fit of cylinders, except in this case the two parts are circular pipes or toroids (see word doc for pic). Because the two toroids are cooled by water at different temperatures they'll see different radial expansion and as such will see...
I want to include the ground with a certain stiffness as a restraint to a structure rather than assume that the ground provides a rigid restraint. Is there an easy way of doing this rather than adding spring elements to every single node at ground level?
corus
Using surface plot to create a 2D contour from a rectangular grid of data, I find that even though no grid lines are specified, the chart includes a grid, or black outline, for each cell of data. How do you remove the black outlines so as to leave just continuous colour?
corus
I've been given the material properties of a steel (in terms of the young's modulus) taken from one sample. I have my doubts that the value is accurate. Is there a design standard for testing material that specifies, say, the number of samples to be taken to obtain an average, or the method of...
Probably a simple question, but when reporting the results and viewing the Word document or html doculment from another pc, the pictures have disappeared. I presume they were in the orginal documents as a link, but when the file is forwarded on, this link is lost. How do you get the pictures to...
Using MathCad 13, I've pasted pictures into the document using paste special and bitmap format and have been able to view the contents ok, scrolling up and down the pages. The next day when I load the file again, the pictures don't show although the frame box is there when clicked on. Scrolling...
With gusset plates I've heard that it's better to weld the gusset plate right into the corner, whereas others say that it's best practice to use a mouse hole in the corner and only weld up to the edge of the mouse hole.
In terms of strength and fatigue life, what are the arguments for each...
A bulge has formed in a pressure vessel wall under circumstances which are known, but are unlikely to happen again. Is there a method by which it can be determined if the area of the bulge needs to be replaced? I've seen out of roundness tests in pressure vessel codes before, but how do you...
I've seen references to yield stress that is dependent upon the strain rate that the load is applied, ie. that the apparent yield stress increases with the rate at which the load is applied, as under impact.
Should the allowable stress for impact loads be increased as compared to an equivalent...
In BS4604 it refers to calculating the torque applied to a bolt based upon 0.6 of the proof load, or UTS as I read it. For fatigue applications, however, it says that only 0.5 of the proof load should be used. This appears contradictory to the advice usually given to torque the bolt to almost...
Why won't MathCad 13 let you use a variable as an exponent?
For instance when
k=2
d=10m
the expression d^k gives an error saying the exponention operator requires a constant value when applied to a value with units. This seemed to work in MathCad 11.
corus
