An article “Flexural Design of Reinforced Concrete Beam Sections” by Qian Wang and Shahriar Quayyum was published in Structure magazine in two parts; Part 1 April 2023 and Part 2 June 2023. This was the prompt for a recently posted worked example; “Beam section”.
A ‘Files’ section has been added to the General volume of the User Guide. This includes a download button for a pdf file that gives a detailed description of the XSF cross section files.
It presents details of the XSF that are not really needed for the normal use of the application. The purpose is to provide transparency. The concept of a black box that crunches the numbers is not helpful.
Version 5.11 has been released for the Apple iPhone and iPad. The bug that affected the format of the numeric keyboard on the iPhone has been fixed.
An update of the General volume of the User Guide is available as a pdf file. The download button on the title page of the posted General volume now downloads this new pdf file. This new volume is dated December 2022 and it is intended that it will be posted on the web site with appropriate internal cross-reference links.
The application version 5.10 on the Apple iPhone has a bug in the load-case edit facilities that affects the numeric keyboard. At times this keyboard is not formatted correctly so that part is obscured.
When this occurs reorient the display from portrait to landscape and back again. This will fix it. Alternatively exit the load-case edit facilities back to the load-case list and then select the load-case to reenter the edit facilities again. This will also fix it.
In each session of the use of the application this problem can occur only once for each of numbers, exponents and metric prefixes.
This bug does not affect the application on the Apple iPad or any other device.
Version 5.10 has been released for the Apple iPhone and iPad.
The facilities to choose a subject location have been improved: a Choose button and a Cancel button have been added. A number of bugs have been fixed. These were in the user interface and would not have affected the computation results.
There is to be an addition to the General volume of the User Guide about ‘subject location’ and associated minor changes to the Android phone, iPhone and iPad volume.
Version 5.9 for the Apple Mac device has been released. The user control of the automatic trial and adjustment has been improved. Some bugs have been fixed.
Version 5.9 for the Microsoft Windows device has been released. The user control of the automatic trial and adjustment has been improved. Some bugs have been fixed.
The download button in the Android phone & iPhone guide now downloads a pdf file of the November 2021 version of that volume of the user guide. This includes for the Apple iPad. The text displayed on the web site though is still the older version.
Version 5.9 has been released for the iPhone and also the intended use of the application has been extended to the iPad.
The user control of the automatic trial and adjustment has been improved. A switch controls the progress display. When this is not showing the computations are much faster.
The extra display area of the iPad is used to make more direct use of the graphical representations of the cross section and the material stress/strain relationships.
On the iPhone the style of the display has been improved. The appearance has changed although it works much the same.
There are minor changes to the User Guide describing these improvements use on the iPhone.
The use of the app on the iPad has similarities with its use on the iPhone. In the first instance it is envisaged the existing User Guide for the iPhone and Android phone should suffice for the iPad: what is different is obvious and its use intuitive. Nevertheless, the Users Guide is to be modified to formally accommodate the iPad. Intuition should not be necessary.
For the meantime a description of what is different follows.
iPad iPhone differences
On the iPad there are no Next and Back button in the top corners of the display. Rather, there are buttons with self explanatory captions on the various dialog and data panels, generally near the bottom of the panel.
Data is on panels that overlay a graphic image
A graphical representations of the cross-section or of a material’s stress/strain relationship occupies the whole display on the iPad. The data and other information is presented in panels that overlay that image. Each of these panels can either be hidden or can be moved about so that all parts of the image can be seen.
One of these panels has the main tab buttons ‘F’, ‘M’, ‘C’, ‘L’ and ‘T’ and presents the lists of the various kinds of entities: files, materials, components, load cases and time affect sets.
As with the previous versions a tap on an entity name in these lists will open the editor for that entity. Generally the background for these editors is an image of the cross-section although the background for the material editor is the stress/strain relationship of the material.
Information that pertains to a particular feature is presented on a panel that can be moved so that always that feature can be revealed. Near each corner of these panels is a small button labeled ‘TL’, ‘TR’ … etc. A tap on these buttons will move the panel.
TL = Top left corner of the display
TR = Top right corner of the display
BR = Bottom right corner of the display
BC = Bottom centre of the display
BL = Bottom left corner of the display
C = Centre of the display
The virtual alpha numeric keyboard for entity names occupies the bottom of the display. The place for the new entity name is always near the top.
The virtual numeric keyboard is always at the bottom. When the number to be edited is on a moveable panel the keyboard has move buttons each side. It can be moved from side to side across the bottom so that always the feature to be edited can be seen.
The image in the background
When the application is started, or the selected xsf file is deleted the background to the file list panel is black. When a new file is created or an existing file is selected the background becomes white and the components described in the file are shown in black.
A subject component is highlighted on the cross-section image: the other components are grayed. Also there is a little red circle that acts as a cursor indicating a particular feature that is the subject.
Editing changes that affect the image are immediately reflected by changes to the image.
Load case graphics
The reference point is indicated by a little blue circle and the reference axis is also shown in blue.
With the load case editing facilities what is of interest is indicated by circles of a dark cyan color. These circles are slightly larger than the red cursor circle.
Two concentric circles indicate the point with the focus in the three point method, while the other two points are indicated by single circles.
Two concentric circles also indicate the subject of a yield computation.
With a computation result display three concentric circles indicate the location of the axial load (if there is an axial load). If this is outside the area that displays the cross-section the scale of the image is reduced so that it is accommodated. The axial load can possibly be some distance from the cross section so that the reduction is scale affects the readability of the cross section image. There is a button to hide the axial load location that overcomes this problem.
Editing the graphic image
When the selected file has no components the background will be white. As components are added the image display will remain blank white until there are objects with more than one X value and more than one Y value.
Here the word ‘object’ means either a corner of a shape component, a point in a point component or a stress/strain in the description of a material. These objects are in a sequence and are numbered; 0, 1, 2, …. .
The data pertaining to an individual object is presented on a moveable panel. These panels are similar to corresponding displays on the iPhone with two toolbars at the top, although the top toolbar has only one button being the ‘+’ button. The second toolbar is the same as that on the iPhone: the Next and Back buttons moving the subject forward and backward through the sequence of objects. Also the object kind and sequence number is indicated by a label in the centre of the toolbar.
The red cursor circle indicates the subject object on the graphic image. Also in the case of a shape component or a stress/strain relationship the line between the subject object and the next object is red. This is intended to indicate where an added new object would appear.
The ‘+’ button in the top right corner will add an object in the sequence after the object that is the subject. If the subject object is not the last the new object will have X, Y values that are half way between that subject object and the next object. Those new X, Y values can then be changed to whatever is required. If, on the other hand, that subject object was the last the new object X, Y values are copied from that subject object. Although those new X, Y values can still be changed to whatever is required the new object is not obvious on the graphic image. In a point component such lost objects make the computations erroneous. The automatic geometry check that happens when a load case is opened should pick up such lost points. The error message is ‘Point components clash at …’.
As with the previous versions a tap on the object identifier on the toolbar will cause a red delete button to appear and a tap on that will delete that object from the sequence.
Also, as with the previous version when an object is added or deleted the sequence numbers are reassigned to all the objects after that added or deleted object.
Similar panels are use for the result details display that presents information about an individual object. On these panels the top toolbar is replaced by a selection box so the user can select the component of interest.