Propped cantilever by double integration, step by step — a TI-89 Titanium program

By E-Code · updated 2026-09-26

PROPBEAM is a TI-89 BASIC program for the TI-89 Titanium. A beam fixed at A and on a roller at B, with a uniform load w and a point load P. Every step on its own screen, the way you write it up: the moment equation, the CAS integrating twice (Macaulay terms), the boundary conditions, the CAS solving for the redundant reaction RB, then RA, the wall moment and the largest sagging moment.

What it asks for and what it shows

It asks for 4 values at its prompts. In the example below it shows RB kN, RA kN, MA kN*m, M+max kN*m, at x m, 1 MOMENT (x from B), 2 INTEGRATE (CAS), 3 BOUNDARY CONDITIONS, 4 SOLVE BOTH (CAS), 7 ANSWER (x from B).

Example run

One of its oracle test cases. The inputs are typed in order, and the results are the values the case expects on the screen.

Step	Value
You enter
Input 1	10
Input 2	6
Input 3	20
Input 4	2
The screen shows
`RB kN=`	25.46296296
`RA kN=`	54.53703704
`MA kN*m=`	-67.22222222
`M+max kN*m=`	32.41812414
`at x m=`	2.546296296
Text	1 MOMENT (x from B)
Text	2 INTEGRATE (CAS)
Text	3 BOUNDARY CONDITIONS
Text	4 SOLVE BOTH (CAS)
Text	7 ANSWER (x from B)

How it's checked

6 test cases, each checked against an independent method. Replayed key by key on a virtual TI-89 Titanium, they make 72 checks.

How E-Code checks every program

Run it or put it on your calculator

Open the library in the TI-89 Titanium calculator and pick “Propped cantilever by double integration, step by step” (PROPBEAM).
Put it on your own calculator with a computer and a USB cable, or type it in by hand.

Related programs

All TI-89 Titanium engineering programs · All TI-89 Titanium programs