diff --git a/docs/help/beam.idraw b/docs/help/beam.idraw new file mode 100644 index 0000000..77177cf Binary files /dev/null and b/docs/help/beam.idraw differ diff --git a/docs/help/beam.png b/docs/help/beam.png new file mode 100644 index 0000000..58d7d18 Binary files /dev/null and b/docs/help/beam.png differ diff --git a/docs/help/theory.4ct b/docs/help/theory.4ct index e9a7610..3241f03 100644 --- a/docs/help/theory.4ct +++ b/docs/help/theory.4ct @@ -1,9 +1,10 @@ \expandafter\ifx\csname doTocEntry\endcsname\relax \expandafter\endinput\fi \doTocEntry\tocsection{1}{\csname a:TocLink\endcsname{1}{x1-10001}{QQ2-1-1}{Introduction}}{3}\relax -\doTocEntry\tocsection{2}{\csname a:TocLink\endcsname{1}{x1-20002}{QQ2-1-2}{Kinematics}}{3}\relax -\doTocEntry\tocsection{3}{\csname a:TocLink\endcsname{1}{x1-30003}{QQ2-1-3}{Constitutive relations}}{4}\relax -\doTocEntry\tocsection{4}{\csname a:TocLink\endcsname{1}{x1-40004}{QQ2-1-4}{Stress resultants}}{5}\relax -\doTocEntry\tocsection{5}{\csname a:TocLink\endcsname{1}{x1-50005}{QQ2-1-5}{Equilibrium}}{7}\relax -\doTocEntry\tocsection{6}{\csname a:TocLink\endcsname{1}{x1-60006}{QQ2-1-6}{Governing equation}}{9}\relax -\doTocEntry\tocsection{7}{\csname a:TocLink\endcsname{1}{x1-70007}{QQ2-1-7}{Finding moment, shear force, and slope from the displacement function}}{10}\relax +\doTocEntry\toclof{1}{\csname a:TocLink\endcsname{1}{x1-10011}{}{\ignorespaces Deformation of the Bernoulli-Euler beam. Definition of coordinate axes and components of displacement.}}{figure}\relax +\doTocEntry\tocsection{2}{\csname a:TocLink\endcsname{1}{x1-20002}{QQ2-1-3}{Kinematics}}{6}\relax +\doTocEntry\tocsection{3}{\csname a:TocLink\endcsname{1}{x1-30003}{QQ2-1-4}{Constitutive relations}}{7}\relax +\doTocEntry\tocsection{4}{\csname a:TocLink\endcsname{1}{x1-40004}{QQ2-1-5}{Stress resultants}}{8}\relax +\doTocEntry\tocsection{5}{\csname a:TocLink\endcsname{1}{x1-50005}{QQ2-1-6}{Equilibrium}}{10}\relax +\doTocEntry\tocsection{6}{\csname a:TocLink\endcsname{1}{x1-60006}{QQ2-1-7}{Governing equation}}{11}\relax +\doTocEntry\tocsection{7}{\csname a:TocLink\endcsname{1}{x1-70007}{QQ2-1-8}{Finding moment, shear force, and slope from the displacement function}}{12}\relax \par diff --git a/docs/help/theory.4tc b/docs/help/theory.4tc index cc35da8..d13b88e 100644 --- a/docs/help/theory.4tc +++ b/docs/help/theory.4tc @@ -1,8 +1,9 @@ \expandafter\ifx\csname doTocEntry\endcsname\relax \expandafter\endinput\fi \doTocEntry\tocsection{1}{\csname a:TocLink\endcsname{1}{x1-10001}{QQ2-1-1}{Introduction}}{3}\relax -\doTocEntry\tocsection{2}{\csname a:TocLink\endcsname{1}{x1-20002}{QQ2-1-2}{Kinematics}}{3}\relax -\doTocEntry\tocsection{3}{\csname a:TocLink\endcsname{1}{x1-30003}{QQ2-1-3}{Constitutive relations}}{4}\relax -\doTocEntry\tocsection{4}{\csname a:TocLink\endcsname{1}{x1-40004}{QQ2-1-4}{Stress resultants}}{5}\relax -\doTocEntry\tocsection{5}{\csname a:TocLink\endcsname{1}{x1-50005}{QQ2-1-5}{Equilibrium}}{7}\relax -\doTocEntry\tocsection{6}{\csname a:TocLink\endcsname{1}{x1-60006}{QQ2-1-6}{Governing equation}}{9}\relax -\doTocEntry\tocsection{7}{\csname a:TocLink\endcsname{1}{x1-70007}{QQ2-1-7}{Finding moment, shear force, and slope from the displacement function}}{10}\relax +\doTocEntry\toclof{1}{\csname a:TocLink\endcsname{1}{x1-10011}{}{\ignorespaces Deformation of the Bernoulli-Euler beam. Definition of coordinate axes and components of displacement.}}{figure}\relax +\doTocEntry\tocsection{2}{\csname a:TocLink\endcsname{1}{x1-20002}{QQ2-1-3}{Kinematics}}{6}\relax +\doTocEntry\tocsection{3}{\csname a:TocLink\endcsname{1}{x1-30003}{QQ2-1-4}{Constitutive relations}}{7}\relax +\doTocEntry\tocsection{4}{\csname a:TocLink\endcsname{1}{x1-40004}{QQ2-1-5}{Stress resultants}}{8}\relax +\doTocEntry\tocsection{5}{\csname a:TocLink\endcsname{1}{x1-50005}{QQ2-1-6}{Equilibrium}}{10}\relax +\doTocEntry\tocsection{6}{\csname a:TocLink\endcsname{1}{x1-60006}{QQ2-1-7}{Governing equation}}{11}\relax +\doTocEntry\tocsection{7}{\csname a:TocLink\endcsname{1}{x1-70007}{QQ2-1-8}{Finding moment, shear force, and slope from the displacement function}}{12}\relax diff --git a/docs/help/theory.aux b/docs/help/theory.aux index c03ad1f..1db4859 100644 --- a/docs/help/theory.aux +++ b/docs/help/theory.aux @@ -1,19 +1,20 @@ \relax \ifx\rEfLiNK\UnDef\gdef \rEfLiNK#1#2{#2}\fi -\newlabel{Eq:1}{{\rEfLiNK{x1-2001r1}{1}}{\rEfLiNK{x1-2001r1}{4}}} -\newlabel{Eq:2}{{\rEfLiNK{x1-2002r2}{2}}{\rEfLiNK{x1-2002r2}{4}}} -\newlabel{Eq:3}{{\rEfLiNK{x1-3001r3}{3}}{\rEfLiNK{x1-3001r3}{5}}} -\newlabel{Eq:4}{{\rEfLiNK{x1-3002r4}{4}}{\rEfLiNK{x1-3002r4}{5}}} -\newlabel{Eq:5}{{\rEfLiNK{x1-4001r5}{5}}{\rEfLiNK{x1-4001r5}{6}}} -\newlabel{Eq:6}{{\rEfLiNK{x1-4002r6}{6}}{\rEfLiNK{x1-4002r6}{6}}} -\newlabel{Eq:7}{{\rEfLiNK{x1-4003r7}{7}}{\rEfLiNK{x1-4003r7}{6}}} -\newlabel{Eq:7b}{{\rEfLiNK{x1-4004r8}{8}}{\rEfLiNK{x1-4004r8}{7}}} -\newlabel{Eq:8}{{\rEfLiNK{x1-5001r9}{9}}{\rEfLiNK{x1-5001r9}{7}}} -\newlabel{Eq:9}{{\rEfLiNK{x1-5002r10}{10}}{\rEfLiNK{x1-5002r10}{8}}} -\newlabel{Eq:10}{{\rEfLiNK{x1-5003r11}{11}}{\rEfLiNK{x1-5003r11}{8}}} -\newlabel{Eq:11}{{\rEfLiNK{x1-6001r12}{12}}{\rEfLiNK{x1-6001r12}{9}}} -\newlabel{Eq:12}{{\rEfLiNK{x1-6002r13}{13}}{\rEfLiNK{x1-6002r13}{9}}} -\newlabel{Eq:13}{{\rEfLiNK{x1-7001r14}{14}}{\rEfLiNK{x1-7001r14}{10}}} -\newlabel{Eq:14}{{\rEfLiNK{x1-7002r15}{15}}{\rEfLiNK{x1-7002r15}{10}}} -\newlabel{Eq:15}{{\rEfLiNK{x1-7003r16}{16}}{\rEfLiNK{x1-7003r16}{11}}} -\newlabel{Eq:16}{{\rEfLiNK{x1-7004r17}{17}}{\rEfLiNK{x1-7004r17}{11}}} +\newlabel{Fig:1}{{\rEfLiNK{x1-10001}{1}}{\rEfLiNK{x1-10001}{5}}} +\newlabel{Eq:1}{{\rEfLiNK{x1-2001r1}{1}}{\rEfLiNK{x1-2001r1}{6}}} +\newlabel{Eq:2}{{\rEfLiNK{x1-2002r2}{2}}{\rEfLiNK{x1-2002r2}{7}}} +\newlabel{Eq:3}{{\rEfLiNK{x1-3001r3}{3}}{\rEfLiNK{x1-3001r3}{7}}} +\newlabel{Eq:4}{{\rEfLiNK{x1-3002r4}{4}}{\rEfLiNK{x1-3002r4}{8}}} +\newlabel{Eq:5}{{\rEfLiNK{x1-4001r5}{5}}{\rEfLiNK{x1-4001r5}{8}}} +\newlabel{Eq:6}{{\rEfLiNK{x1-4002r6}{6}}{\rEfLiNK{x1-4002r6}{9}}} +\newlabel{Eq:7}{{\rEfLiNK{x1-4003r7}{7}}{\rEfLiNK{x1-4003r7}{9}}} +\newlabel{Eq:7b}{{\rEfLiNK{x1-4004r8}{8}}{\rEfLiNK{x1-4004r8}{9}}} +\newlabel{Eq:8}{{\rEfLiNK{x1-5001r9}{9}}{\rEfLiNK{x1-5001r9}{10}}} +\newlabel{Eq:9}{{\rEfLiNK{x1-5002r10}{10}}{\rEfLiNK{x1-5002r10}{11}}} +\newlabel{Eq:10}{{\rEfLiNK{x1-5003r11}{11}}{\rEfLiNK{x1-5003r11}{11}}} +\newlabel{Eq:11}{{\rEfLiNK{x1-6001r12}{12}}{\rEfLiNK{x1-6001r12}{12}}} +\newlabel{Eq:12}{{\rEfLiNK{x1-6002r13}{13}}{\rEfLiNK{x1-6002r13}{12}}} +\newlabel{Eq:13}{{\rEfLiNK{x1-7001r14}{14}}{\rEfLiNK{x1-7001r14}{13}}} +\newlabel{Eq:14}{{\rEfLiNK{x1-7002r15}{15}}{\rEfLiNK{x1-7002r15}{13}}} +\newlabel{Eq:15}{{\rEfLiNK{x1-7003r16}{16}}{\rEfLiNK{x1-7003r16}{14}}} +\newlabel{Eq:16}{{\rEfLiNK{x1-7004r17}{17}}{\rEfLiNK{x1-7004r17}{14}}} diff --git a/docs/help/theory.dvi b/docs/help/theory.dvi index b6e694b..47f3439 100644 Binary files a/docs/help/theory.dvi and b/docs/help/theory.dvi differ diff --git a/docs/help/theory.html b/docs/help/theory.html index f9d0851..9022c79 100644 --- a/docs/help/theory.html +++ b/docs/help/theory.html @@ -21,76 +21,113 @@
This tool employs the Bernoulli-Euler beam theory. This theory, also +
+
+
This tool employs the Bernoulli-Euler beam theory. This theory, also known as shear rigid beam theory, is based on the kinematic assumption that
Any plane cross section perpendicular to the undeformed beam’s +
Any plane cross section perpendicular to the undeformed beam’s axis remain plane and perpendicular to the axis throughout the deformation.
This allows us to reduce the three-dimensional problem to a single unknown +
This allows us to reduce the three-dimensional problem to a single unknown function, v(x), known as deflection of the beam. -
Navier’s assumption leads to +
Navier’s assumption leads to
-
| (1) |
+
+This displacement field induces an axial strain of
+
| (2) |
-
+
+Equation (2) states that a fiber parallel to the beam axis stretches in the bottom +portion of the beam (y < 0) and contracts if the fiber is located above the beam +axis (y > 0). The beam axis itself does not stretch. +
For a slender beam, we can ignore stress components acting perpendicular to the +beam’s axis. Thus, the constitutive relations can be simplified as the 1D-version +of Hooke’s law: +
![]() | (3) |
+
+where E is the modulus of elasticity. +
The imposed state of deformation induces normal stress proportional to the +strain field (2) as
+
| (4) |
-
+
+This relation states that (i) the stress varies linearly with the distance from the +beam’s axis, vanishing at the axis, and (ii) the stress is proportional to the +curvature of the beam. +
The beam sees two stress resultants: the internal moment, +
The beam sees two stress resultants: the internal moment,
4 | (5) |
+
and the transverse shear force,
+
![]() | (6) |
+
Substituting (4) into (5) yields @@ -124,27 +162,27 @@
+
where
-
![]() | (8) |
+ +
is the area moment of inertia or, short, moment of inertia. -
Note that the modulus of elasticity, Note that the modulus of elasticity, E, characterizes the material, the
moment of inertia, I, characterized the shape of the cross section, and the second
@@ -153,11 +191,11 @@ 4 ′′
(x), characterizes the deformation (curvature) of
the beam.
-
+
Equilibrium is formulated in terms of shear forces, Equilibrium is formulated in terms of shear forces, V (x), and internal moments,
5
+
where w(x) is the distributed lateral load per length. 5 x) is defined positive if pointing against the (upward) positive y-axis. - -
Moment equilibrium around the out-of-plane axis on the same element +
Moment equilibrium around the out-of-plane axis on the same element yields
+
![]() | (10) |
+
A system for which equations (9) and (10) are sufficient to determine the @@ -204,7 +242,7 @@
Equations ( Equations (9) and (10) may be combined into one equation as
+
Equation (11) replaces both equilibrium equations (9) and (10).
-
-
+
The governing equation is obtained by assuming the displacement function,
+ The governing equation is obtained by assuming the displacement function,
v(x), as the primary unknown and expressing 6 11) using (7) to
obtain
+
5
(11)
-6 Governing equation
-
| (12) |
+
This equation is known as the governing equation of the Bernoulli-Euler beam. -
If the beam possesses a constant cross section and is made of one material, +
If the beam possesses a constant cross section and is made of one material,
then EI(x) = 6
+
Equation (13) is what is implemented in this program. - -
+
Solving ( Solving (13) and applying suitable boundary conditions yields the displacement
function, v(7
+
It is positive if the cross section rotates counter-clockwise during deformation. -
The moment follows from ( The moment follows from (7) as
(15) |
+
The transverse shear force follows from (11) as
+
![]() | (16) |
+
or, for constant EI, simplifies to
@@ -324,7 +361,7 @@+