Plain-English steelwork glossary

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. G is permanent load; Q is imposed load. A surface load and a line load also have different units.
2. This illustration uses the course gravity case $1.4G+1.6Q$. Other combinations in the original text retain their own factors.
3. For illustrative $G=5\frac{\text{kN}}{{\text{m}}^2}$, change Q and watch each separate contribution.
4. Do not carry this ULS total automatically into deflection. Follow the stated SLS load case.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. A column can bow sideways before its section reaches the crushing resistance.
2. Each axis has its own radius of gyration and restraint spacing.
3. $\lambda =\frac{L_E}{r}$, with compatible length units. A tie affects only the directions it actually restrains.
4. Select each buckling curve and compressive strength before forming Pc. The governing axis is determined by resistance, not slenderness alone.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. Force transfers through contact between bolt and connected plate.
2. The plate around the hole carries bearing stress. Bolt bearing and plate bearing are separate checks.
3. A short ligament can tear out towards the end. The direction of force determines the relevant edge.
4. Evaluate every specified bearing and ligament bound for each layer and retain the smallest applicable resistance.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. For sagging, the top flange is in compression and the bottom in tension; hogging reverses this.
2. Elastic bending stress varies with distance from the neutral axis: $\sigma =\frac{My}{I}$.
3. The section class governs whether elastic, plastic or effective properties may be used.
4. Use the shear at the section under examination; the largest shear elsewhere is not automatically coexistent.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. A block containing the connection can detach from the surrounding plate.
2. The paths parallel to the applied force carry shear.
3. The closing path across the end of the block carries tension.
4. Use the specified gross/net deductions and resistance expression. This is different from a single straight net-section fracture.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. A column can bow sideways before its section reaches the crushing resistance.
2. Each axis has its own radius of gyration and restraint spacing.
3. $\lambda =\frac{L_E}{r}$, with compatible length units. A tie affects only the directions it actually restrains.
4. Select each buckling curve and compressive strength before forming Pc. The governing axis is determined by resistance, not slenderness alone.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. The centre is empty: resistance comes from the weld lines, not a solid plate filling the group.
2. Use line lengths for centroid weighting. Line second moments have units ${\text{mm}}^3$; add the parallel-axis terms.
3. Direct force per length is $\frac{P}{L}$. The eccentric moment adds tangential flow proportional to distance from the centroid.
4. Combine signed components at every candidate corner, then compare the maximum with throat resistance per length.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. G is permanent load; Q is imposed load. A surface load and a line load also have different units.
2. This illustration uses the course gravity case $1.4G+1.6Q$. Other combinations in the original text retain their own factors.
3. For illustrative $G=5\frac{\text{kN}}{{\text{m}}^2}$, change Q and watch each separate contribution.
4. Do not carry this ULS total automatically into deflection. Follow the stated SLS load case.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. The flange outstand and web have different widths, thicknesses and edge support conditions.
2. A thinner plate can wrinkle locally before the complete member loses stability.
3. Class 1 allows plastic rotation; Class 2 reaches plastic resistance; Class 3 reaches elastic resistance; Class 4 requires effective properties.
4. Check every relevant compression element with the supplied limits and stress distribution. The deformation shown is qualitative.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. For the illustrated sagging beam the top flange is compressed.
2. The unrestrained compression flange can move sideways while the complete cross-section twists.
3. Only effective restraints divide the member into unbraced segments. They do not automatically add vertical supports.
4. Use the segment effective length, section properties and matching moment factor. This is an exaggerated mode shape, not a calculated displacement.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. G is permanent load; Q is imposed load. A surface load and a line load also have different units.
2. This illustration uses the course gravity case $1.4G+1.6Q$. Other combinations in the original text retain their own factors.
3. For illustrative $G=5\frac{\text{kN}}{{\text{m}}^2}$, change Q and watch each separate contribution.
4. Do not carry this ULS total automatically into deflection. Follow the stated SLS load case.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. Use the specified SLS load, span and support arrangement. The demonstrator has a full-span UDL.
2. The loaded beam bends; the deformation is exaggerated so its shape can be seen.
3. For a simply supported full-span UDL, $\delta =\frac{5w{L}^4}{384EI}$. Double L with w, E and I unchanged: δ becomes 16 times as large.
4. The readout uses $w=10\frac{\text{N}}{\text{mm}}$, $E=205000\frac{\text{N}}{{\text{mm}}^2}$ and $I=200000000{\text{mm}}^4$. Select the finish/support-specific limit from the original table.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. Name the required property: material strength, section property, buckling strength or a moment factor.
2. Keep section size, steel grade, thickness band, curve and axis as separate lookup keys.
3. ${\text{cm}}^2$, ${\text{cm}}^3$ and ${\text{cm}}^4$ require different conversion powers. Do not use adjacent columns interchangeably.
4. Use bracketing rows within the same valid column. The original page remains the source of all table values.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. Stress is force divided by area. Strain measures change in length relative to original length.
2. Before yielding, stress is approximately $E\times \text{strain}$. E controls the elastic slope.
3. Further strain includes permanent deformation. Higher yield strength does not by itself increase E.
4. Strength, stiffness and ductility answer different questions. This schematic is not a measured stress–strain curve.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. A beam reaction can act away from the column centre even at a nominally pinned beam connection.
2. $M=Re$. Opposing reactions can cancel part of the signed moment, while both still add compression.
3. The course simple model distributes the joint moment in proportion to $\frac{I}{L}$ of the columns above and below.
4. Equal relevant stiffness gives half each. A roof joint with no upper column is a different case.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. Gross area counts the complete plate width and thickness.
2. The highlighted transverse path passes through the bolt holes.
3. For the straight illustrative path, $A_n=(b-n{d}_0)t$. Staggered paths require their specified correction.
4. Net area is not always effective area. Include the course’s strength ratio or shear-lag rule when applicable.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. A column can bow sideways before its section reaches the crushing resistance.
2. Each axis has its own radius of gyration and restraint spacing.
3. $\lambda =\frac{L_E}{r}$, with compatible length units. A tie affects only the directions it actually restrains.
4. Select each buckling curve and compressive strength before forming Pc. The governing axis is determined by resistance, not slenderness alone.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. The flanges are the wide plates; the web connects them. Rotate the I-section to see both.
2. The same section has different stiffness and resistance about its two principal axes.
3. I controls elastic curvature; $Z=\frac{I}{y_{\max }}$ is elastic section modulus. Plastic modulus S comes from plastic stress blocks.
4. Nominal section labels are not every actual dimension. Keep the row, axis and units together.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. Hole diameter d₀ differs from nominal bolt diameter d. Net-section deductions use the specified hole.
2. Pitch runs along the load direction; gauge measures spacing across rows.
3. End and edge distances start at the hole centre. The remaining ligament starts at the hole boundary.
4. Minimum spacing, edge distances, grip and plate thickness come from the specified rules, not this scaled illustration.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. An equal-leg fillet between perpendicular plates has an approximately right-triangular section.
2. For this geometry, throat $a\approx 0.7s$. It is shorter than the leg.
3. Effective resisting area = $a\times L_{\mathrm{eff}}$. With $p_w=220\frac{\text{N}}{{\text{mm}}^2}$ here, capacity per length is $0.7s\times 220\frac{\text{N}}{\text{mm}}$.
4. Use the course end allowances, minimum size and length rules; increasing the geometric length alone does not resolve every detailing check.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. The flanges are the wide plates; the web connects them. Rotate the I-section to see both.
2. The same section has different stiffness and resistance about its two principal axes.
3. I controls elastic curvature; $Z=\frac{I}{y_{\max }}$ is elastic section modulus. Plastic modulus S comes from plastic stress blocks.
4. Nominal section labels are not every actual dimension. Keep the row, axis and units together.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. Hole diameter d₀ differs from nominal bolt diameter d. Net-section deductions use the specified hole.
2. Pitch runs along the load direction; gauge measures spacing across rows.
3. End and edge distances start at the hole centre. The remaining ligament starts at the hole boundary.
4. Minimum spacing, edge distances, grip and plate thickness come from the specified rules, not this scaled illustration.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. Gross area counts the complete plate width and thickness.
2. The highlighted transverse path passes through the bolt holes.
3. For the straight illustrative path, $A_n=(b-n{d}_0)t$. Staggered paths require their specified correction.
4. Net area is not always effective area. Include the course’s strength ratio or shear-lag rule when applicable.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. Use the specified SLS load, span and support arrangement. The demonstrator has a full-span UDL.
2. The loaded beam bends; the deformation is exaggerated so its shape can be seen.
3. For a simply supported full-span UDL, $\delta =\frac{5w{L}^4}{384EI}$. Double L with w, E and I unchanged: δ becomes 16 times as large.
4. The readout uses $w=10\frac{\text{N}}{\text{mm}}$, $E=205000\frac{\text{N}}{{\text{mm}}^2}$ and $I=200000000{\text{mm}}^4$. Select the finish/support-specific limit from the original table.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. Shear and tension, or compression and bending, must refer to the same bolt or checked section.
2. Divide every action by the resistance prescribed for that term.
3. The bars illustrate a linear sum only. Bolt interaction can have a different limit and individual checks; retain the original expression.
4. A pass in one interaction does not prove all failure modes pass. Read the exact calculation in the source player below.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. For the illustrated sagging beam the top flange is compressed.
2. The unrestrained compression flange can move sideways while the complete cross-section twists.
3. Only effective restraints divide the member into unbraced segments. They do not automatically add vertical supports.
4. Use the segment effective length, section properties and matching moment factor. This is an exaggerated mode shape, not a calculated displacement.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. For the illustrated sagging beam the top flange is compressed.
2. The unrestrained compression flange can move sideways while the complete cross-section twists.
3. Only effective restraints divide the member into unbraced segments. They do not automatically add vertical supports.
4. Use the segment effective length, section properties and matching moment factor. This is an exaggerated mode shape, not a calculated displacement.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. The centre is empty: resistance comes from the weld lines, not a solid plate filling the group.
2. Use line lengths for centroid weighting. Line second moments have units ${\text{mm}}^3$; add the parallel-axis terms.
3. Direct force per length is $\frac{P}{L}$. The eccentric moment adds tangential flow proportional to distance from the centroid.
4. Combine signed components at every candidate corner, then compare the maximum with throat resistance per length.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. Moment ordinates must belong to the same effective unbraced segment.
2. Same-side and reverse-curvature diagrams have different signed end ratios.
3. The markers show ¼, ½ and ¾ of this segment, not of the entire beam.
4. LTB and column flexural factors are different. Preserve their individual bounds and coefficient sets.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. Gross area counts the complete plate width and thickness.
2. The highlighted transverse path passes through the bolt holes.
3. For the straight illustrative path, $A_n=(b-n{d}_0)t$. Staggered paths require their specified correction.
4. Net area is not always effective area. Include the course’s strength ratio or shear-lag rule when applicable.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. A bracket moment can create compression at the plate contact and tension in the bolt rows.
2. The original assumed pivot/compression line determines each row distance.
3. Under the elastic row model, a farther tension row attracts more tension. Direct shear may act simultaneously.
4. Flexible plates can add prying force. Use nominal tension and interaction rules exactly as specified by the course.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. The flanges are the wide plates; the web connects them. Rotate the I-section to see both.
2. The same section has different stiffness and resistance about its two principal axes.
3. I controls elastic curvature; $Z=\frac{I}{y_{\max }}$ is elastic section modulus. Plastic modulus S comes from plastic stress blocks.
4. Nominal section labels are not every actual dimension. Keep the row, axis and units together.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. A bracket moment can create compression at the plate contact and tension in the bolt rows.
2. The original assumed pivot/compression line determines each row distance.
3. Under the elastic row model, a farther tension row attracts more tension. Direct shear may act simultaneously.
4. Flexible plates can add prying force. Use nominal tension and interaction rules exactly as specified by the course.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. The flanges are the wide plates; the web connects them. Rotate the I-section to see both.
2. The same section has different stiffness and resistance about its two principal axes.
3. I controls elastic curvature; $Z=\frac{I}{y_{\max }}$ is elastic section modulus. Plastic modulus S comes from plastic stress blocks.
4. Nominal section labels are not every actual dimension. Keep the row, axis and units together.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. This demonstrator is a simply supported 6 m beam with a 60 kN point load; it is not the page’s original loading diagram.
2. $R_B\times L=P\times a$. Moving the load towards B increases $R_B$.
3. $R_A=P-R_B$. The two upward reactions must sum to P.
4. With the load at midspan, $R_A=R_B=30\text{kN}$. End couples, UDLs and overhangs require their own equilibrium terms.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. The flanges are the wide plates; the web connects them. Rotate the I-section to see both.
2. The same section has different stiffness and resistance about its two principal axes.
3. I controls elastic curvature; $Z=\frac{I}{y_{\max }}$ is elastic section modulus. Plastic modulus S comes from plastic stress blocks.
4. Nominal section labels are not every actual dimension. Keep the row, axis and units together.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. For sagging, the top flange is in compression and the bottom in tension; hogging reverses this.
2. Elastic bending stress varies with distance from the neutral axis: $\sigma =\frac{My}{I}$.
3. The section class governs whether elastic, plastic or effective properties may be used.
4. Use the shear at the section under examination; the largest shear elsewhere is not automatically coexistent.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. For the illustrative 60 kN point load on a 6 m simply supported beam, balance the reactions before making a cut.
2. $V=R_A$ and $M=R_{A}x$ before the point load. Moment grows linearly.
3. Shear jumps down by P. To its right, $V=R_A-P$ and $M=R_{A}x-P(x-a)$.
4. For this case, moment is continuous and returns to zero at B. A concentrated applied couple instead creates a moment jump.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. Locate the connected leg, outstanding leg and centroid before using the table.
2. Only the connected leg directly receives the fastener force.
3. The outstanding area may not become equally effective at the same section; this motivates the effective-area rule.
4. Bolted, welded, single-angle and double-angle details can have different rules. Preserve the formula attached to the original case.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. A column can bow sideways before its section reaches the crushing resistance.
2. Each axis has its own radius of gyration and restraint spacing.
3. $\lambda =\frac{L_E}{r}$, with compatible length units. A tie affects only the directions it actually restrains.
4. Select each buckling curve and compressive strength before forming Pc. The governing axis is determined by resistance, not slenderness alone.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. A concentrated reaction first enters through the bearing/contact region.
2. The flange and root geometry spread the force before it enters the web.
3. A wider effective bearing region can reduce local stress for the same force.
4. End distance, stiff bearing length and restraint conditions must come from the original question. This slider is illustrative only.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. A column can bow sideways before its section reaches the crushing resistance.
2. Each axis has its own radius of gyration and restraint spacing.
3. $\lambda =\frac{L_E}{r}$, with compatible length units. A tie affects only the directions it actually restrains.
4. Select each buckling curve and compressive strength before forming Pc. The governing axis is determined by resistance, not slenderness alone.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. The floor carries pressure in $\frac{\text{kN}}{{\text{m}}^2}$. The highlighted strip belongs to one secondary beam.
2. Multiply pressure by tributary width: $w=q\times b$. The illustration uses $q=5\frac{\text{kN}}{{\text{m}}^2}$.
3. A primary beam receives the secondary beam reaction at their connection, not a new full-span UDL.
4. Trace reactions down to columns and foundations. Count each loaded area once.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. ULS compares factored actions with the applicable resistance to yielding, rupture or instability.
2. SLS checks movement, vibration or another specified use requirement.
3. A beam can be strong enough but deflect too much. The two checks need their own loads and denominators.
4. A resistance pass cannot stand in for a serviceability pass. Complete all requested checks.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. Shear and tension, or compression and bending, must refer to the same bolt or checked section.
2. Divide every action by the resistance prescribed for that term.
3. The bars illustrate a linear sum only. Bolt interaction can have a different limit and individual checks; retain the original expression.
4. A pass in one interaction does not prove all failure modes pass. Read the exact calculation in the source player below.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. The flanges are the wide plates; the web connects them. Rotate the I-section to see both.
2. The same section has different stiffness and resistance about its two principal axes.
3. I controls elastic curvature; $Z=\frac{I}{y_{\max }}$ is elastic section modulus. Plastic modulus S comes from plastic stress blocks.
4. Nominal section labels are not every actual dimension. Keep the row, axis and units together.

Supplement to the original lesson. Enable JavaScript to play, step through calculations and rotate 3D models. The following explanation remains readable offline.

1. Stress is force divided by area. Strain measures change in length relative to original length.
2. Before yielding, stress is approximately $E\times \text{strain}$. E controls the elastic slope.
3. Further strain includes permanent deformation. Higher yield strength does not by itself increase E.
4. Strength, stiffness and ductility answer different questions. This schematic is not a measured stress–strain curve.