Steel Beam Web Openings Calculator | AISC DG2 + Eurocode
This Steel Beam with Web Openings Calculator is a preliminary-design tool for circular and rectangular openings in W-shapes, informed by the principles of AISC Design Guide 2 (Steel and Composite Beams with Web Openings).
It uses a transparent, mechanics-based four-hinge Vierendeel model with axial–moment (P–M) interaction in the tees, and reports tee properties, tee shear, tee-column buckling, compactness, gross-section flexure/LTB, deflection and edge-distance checks. It supports unreinforced and flat-bar-reinforced openings, LRFD and ASD, and US/SI units. It does not reproduce the Design Guide 2 interaction curves or design equations — results are indicative and must be confirmed against DG2 by a licensed structural engineer.
For preliminary design only — always verify with a licensed structural engineer.
Steel Beam with Web Openings Calculator DG2-based • preliminary
Check circular or rectangular web openings in steel I-beams — unreinforced or flat-bar reinforced — with a four-hinge Vierendeel model, P–M interaction, tee shear, tee-column buckling and deflection checks.
| Equivalent ho / ao used | — |
| Aspect Ratio ao/ho | — |
| Top Tee Depth tt | — |
| Bottom Tee Depth tb | — |
| Top Tee Area At (incl. bars) | — |
| Bottom Tee Area Ab (incl. bars) | — |
| Top Tee It (elastic) | — |
| Bottom Tee Ib (elastic) | — |
| Top Tee Plastic Moment Mpt | — |
| Bottom Tee Plastic Moment Mpb | — |
| Tee Centroid Lever Arm z | — |
| Pure-Moment Strength at Opening Mm (nominal) | — |
| Pure-Shear Strength at Opening Vm (nominal) | — |
| Shear at Opening Vu | — |
| Moment at Opening Mu | — |
| Check | Demand | Capacity | DCR | Status |
|---|
Capacities include φ (LRFD) or 1/Ω (ASD). Edge distance: “demand” = required clear distance d, “capacity” = clear distance provided.
Design envelope of this tool's four-hinge model (not the DG2 curves). The dot is the factored demand; the dashed line extends to the point where demand reaches the envelope.
Governing DCR as the opening height (or diameter) grows by 10% / 20% / 30%, and the best position found by sweeping x along the span (same opening, same loads):
📄 Formulas Used in This Calculator
▼1. Equivalent rectangle for circular openings
$$\text{Unreinforced: } h_o = D_o,\; a_o = 0.9D_o \qquad \text{Reinforced: } h_o = D_o,\; a_o = 0.45D_o$$The size limit $D_o \le 0.70d$ is checked on the physical diameter.
2. Tee depths (measured from the outer flange face to the opening edge)
$$t_t = \frac{d - h_o}{2} - e \qquad t_b = \frac{d - h_o}{2} + e$$$e > 0$ shifts the opening above mid-depth. Each tee is built from the beam flange ($b_f \times t_f$), the web stem ($t_w \times (t - t_f)$) and, if selected, a reinforcing bar ($n\,b_R \times t_R$) set back from the opening edge by the offset.
3. Tee axial and plastic bending capacity
$$P_{y,i} = \sum F_{y}A \qquad M_{p,i} = \sum F_y\,A\,|y - y_{PNA}| \qquad z = d - \bar y_t - \bar y_b$$$y_{PNA}$ is where the force above equals half the total tee yield force; $\bar y$ is the area centroid measured from the outer flange face.
4. Pure-moment strength at the opening
$$M_m = \min(P_{y,t},\,P_{y,b})\; z \qquad P = \frac{M_u}{z}$$With zero shear the two tees act as a force couple. $P$ is the axial force in each tee caused by the overall moment.
5. Four-hinge shear strength with P–M interaction
$$V_i(P) = \min\!\left(\frac{2\,M_{p,i}\,(1 - P/P_{y,i})}{a_o},\; V_{p,i}\right) \qquad V_m(P) = V_t(P) + V_b(P)$$Each tee forms two hinges (one at each end of the opening). The linear $P$–$M$ reduction lies inside the true convex interaction surface and is therefore conservative.
6. M–V interaction DCR
$$\text{DCR}_{MV} = \frac{1}{s_{max}},\quad s_{max} = \max\{s:\; s\,V_u \le \phi_v V_m(P_n),\; P_n = \tfrac{s\,M_u}{\phi_b z} \le P_{y,min}\}$$The demand point $(M_u, V_u)$ is scaled along a ray until it reaches the design envelope plotted in the results.
7. Vierendeel P–M check per tee (elastic shear split)
$$V_i = V_u\frac{I_i}{I_t + I_b} \qquad M_{v,i} = \frac{V_i\,a_o}{2} \qquad \frac{P}{\phi_b P_{y,i}} + \frac{M_{v,i}}{\phi_b M_{p,i}} \le 1.0$$Each tee is fixed-fixed over $a_o$, so the end moment is $V_i a_o/2$. The elastic split is more conservative than the plastic mechanism in item 5 when the tees differ.
8. Overall shear limit and tee web shear
$$V_p = 0.6F_y(d - 2t_f)t_w \qquad V_u \le \tfrac{2}{3}\phi_v V_p$$ $$V_{p,i} = 0.6F_y\left[t_w(t_i - t_f) + A_{extra}\right] \qquad V_i \le \phi_v V_{p,i}$$Tee shear uses the clear web only (tee depth minus flange thickness). $A_{extra}$ is zero unless you deliberately credit reinforcement. The 2/3 limit should be confirmed against DG2.
9. Tee-column buckling (weak axis)
$$\frac{KL}{r} = \frac{1.2\,a_o}{r_{y}} \qquad P_c = \phi_c F_{cr} A \qquad P/P_c \le 1.0$$$F_{cr}$ per AISC 360 Chapter E; $\phi_c = 0.90$. Bars are credited only when placed on both sides of the web. $K = 1.2$ is an assumption of this tool.
10. Compactness
$$\frac{b_f}{2t_f} \le 0.38\sqrt{E/F_y} \qquad \frac{b_R}{t_R} \le 0.38\sqrt{E/F_y}$$11. Gross-section flexure with LTB (AISC 360 Section F2, Cb = 1.0)
$$M_u \le \phi_b M_n,\quad M_n = \text{per Eqs. F2-1 to F2-3 with } L_p,\,L_r,\,r_{ts},\,J \text{ approximated from the dimensions}$$An overall-beam check at the opening location, independent of the opening mechanics.
12. Live-load deflection
$$\delta_{prim} = \max\left|\iint \frac{M_L(x)}{E I_x}\,dx\,dx\right| \qquad \delta_{open} = \frac{V_{L}\,a_o^3}{12E(I_t + I_b)} \qquad \delta_{prim} + \delta_{open} \le \frac{L}{360}$$$\delta_{prim}$ is found by numerical double integration for the actual support condition, uniform and point loads. The opening term is the full relative displacement across the opening, added without a reduction factor (conservative); it uses $I_t + I_b$, which include any reinforcement. The global $I_x$ is not increased by the bars. Service live load only.
Frequently Asked Questions
Steel Beam with Web Openings Calculator
A walkthrough of every input, formula and result in the web opening checker — with a worked example, common mistakes, and an honest description of what the method does and does not cover.
📄 Contents
1. What Is a Steel Beam Web Opening Calculation?
When mechanical, electrical and plumbing (MEP) trades route ducts, conduit or pipes through the floor structure, they often need to pass through the webs of steel beams. The opening removes web material, so the beam must be checked at that location.
Unlike a standard beam check, a web opening adds failure modes that must be checked independently:
- Vierendeel bending — frame action of the top and bottom tees around the opening
- Moment–shear (M–V) interaction — the overall moment loads the tees axially and erodes their shear strength
- Tee shear — the clear web of each tee carrying its share of the shear
- Tee-column buckling — stability of the compression tee
- Local buckling and flexure — flange compactness, reinforcement outstand, gross-section LTB
- Additional deflection — shear deformation across the opening
The governing U.S. reference is AISC Design Guide 2, Steel and Composite Beams with Web Openings, which treats unreinforced and flat-bar-reinforced openings. This calculator is informed by its principles but implements its own simplified model; see the notice above.
2. Where Engineers Apply Web Opening Calculations
HVAC ducts and plumbing risers cross structural bays; openings preserve floor-to-floor height.
Conduit and drainage pipes cross beams; openings avoid costly reroutes.
Process piping and cable trays through heavy framing, where vibration and dynamic loads need extra care.
Dense MEP coordination where every inch of ceiling space counts.
Existing beams checked when new services are installed.
3. Who Uses It — and What It Gives Them
| User | Typical Need | What the Tool Provides |
|---|---|---|
| Structural Engineer | A fast first-pass screening of an opening before detailed DG2 calculations. | All checks run at once with colour-coded DCRs, the governing check, an M–V envelope plot, and a sweep of positions. |
| MEP Coordinator | Judge whether a requested opening is plausible before sending an RFI. | An indicative pass/marginal/fail verdict — to be confirmed by the engineer of record, never used as approval. |
| Steel Fabricator | A record of the opening and reinforcement assumptions. | A copy-able report listing inputs, tee properties and DCRs. Weld design is not included. |
| EIT / Junior Engineer | Understand how opening size and position change demand. | Visible formulas, sensitivity to opening size, and the effect of moving the opening along the span. |
4. Annotated Steel Beam Web Opening Diagram
The figure identifies the geometric parameters used by the calculator.
Figure 1. Beam elevation with a rectangular opening. d = beam depth; hₒ, aₒ = opening height and length; tt, tb = top and bottom tee depths measured from the outer flange face; x = distance from the left support to the opening centre; L = span. Right: Vierendeel action and the equivalent rectangles for circular openings.
5. Step-by-Step User Guide
- 1Select units and design method
Use the Units toggle for US (in / kips / ksi / ft) or SI (mm / kN / MPa / m). Switching units converts all values already entered. Choose LRFD (φ = 0.90 for bending, shear and compression) or ASD (Ω = 1.67).
- 2Choose a W-shape or enter dimensions
Selecting a shape fills d, bf, tf, tw, Ix and Zx. For other sections type the dimensions; Ix and Zx are then computed from them (the fields clear when you edit a dimension).
- 3Set grade and modulus
Pick A36, A992/A572-50 or A572-60. Fy fills automatically; E defaults to 29,000 ksi (200,000 MPa).
- 4Enter span, supports and loads
Enter the span, the support condition (simply supported, fixed-fixed, or fixed-pinned) and uniform dead and live loads. The span is the distance between reaction points: if the reaction acts at a bolt line, use the bolt-line spacing, and measure x from the same left reaction point. Optionally add up to three point loads (dead and live, with position) for girders. Include beam self-weight in wD. The tool forms 1.2D + 1.6L (LRFD) or D + L (ASD) for strength and uses the live load alone for deflection.
- 5Define the opening
Choose rectangular (ho, ao) or circular (Do). Circular openings are converted to an equivalent rectangle that depends on whether reinforcement is selected. Enter the position x, the eccentricity e (positive = shifted up) and the unbraced length Lb. A red warning appears if the opening exceeds 0.70d.
- 6Choose reinforcement
Start with None. If it fails, choose flat bars at the top and bottom edges. Enter the outstand width bR, thickness tR, the offset of the bar from the opening edge (default 1/2 in., leaving room for the fillet weld), the bar yield strength (at least the beam Fy) and whether bars are on one or both sides of the web. Leave “extra tee shear area” at 0 unless you can justify crediting reinforcement in shear.
- 7Calculate
The tool runs every check, redraws the beam and shear diagram, fills the DCR table and the M–V envelope plot, and sweeps opening size and position for the sensitivity panel.
- 8Copy or print the report
Copy Full Report places inputs, tee properties and DCRs on the clipboard; Print Report prints or saves a PDF. Have a licensed engineer review the outcome.
6. Input Parameters, Valid Ranges and Units
| Parameter | Symbol | US Unit | SI Unit | Notes |
|---|---|---|---|---|
| Beam depth | d | in | mm | Must be positive. |
| Flange width / thickness | bf, tf | in | mm | 2tf must be less than d. |
| Web thickness | tw | in | mm | Controls tee shear. |
| Yield strength / modulus | Fy, E | ksi | MPa | E default 29,000 ksi / 200,000 MPa. |
| Moment of inertia / plastic modulus | Ix, Zx | in⁴, in³ | mm⁴, mm³ | From the table or blank (computed). |
| Span | L | ft | m | Centre-to-centre of supports. |
| Dead / live load | wD, wL | kips/ft | kN/m | Uniform. Include self-weight in wD. |
| Opening size | ho, ao, Do | in | mm | ho or Do ≤ 0.70d. ao/ho > 3 is flagged. |
| Position | x | ft | m | Support centreline to opening centre; 0 < x < L. |
| Eccentricity | e | in | mm | + = above mid-depth. Both tees must be deeper than tf. |
| Point loads (optional) | PD, PL, a | kips, ft | kN, m | Up to three. Position a from the left reaction point. A load over the opening fails. |
| Unbraced length | Lb | ft | m | For gross-section LTB (Cb = 1.0). |
| Bar outstand / thickness | bR, tR | in | mm | bR/tR ≤ 0.38√(E/Fy). |
| Bar offset | — | in | mm | Opening edge to near face of bar; default 1/2 in. for weld access. |
| Extra tee shear area | Aextra | in² | mm² | Default 0; engineering judgement only. |
7. All Formulas Used in the Calculation
The equations below are those implemented in the code. They are a mechanics-based simplification, not the Design Guide 2 equations. All lengths are in inches and forces in kips.
Formula 1 — Equivalent rectangle and tee depths
$$\text{Circular, unreinforced: } h_o = D_o,\ a_o = 0.9D_o \qquad \text{Circular, reinforced: } h_o = D_o,\ a_o = 0.45D_o$$ $$t_t = \frac{d - h_o}{2} - e \qquad t_b = \frac{d - h_o}{2} + e$$What it means: Reinforcing a circular opening shortens its equivalent length to 0.45Do, which greatly reduces the Vierendeel demand. Tee depths are measured from the outer flange face to the opening edge.
Formula 2 — Tee axial and bending capacity
$$P_{y} = \sum F_y A \qquad M_{p} = \sum F_y A\,|y - y_{PNA}| \qquad z = d - \bar y_t - \bar y_b$$What it means: Each tee is built from the beam flange, the web stem and (if present) the reinforcing bar, set back from the opening edge by the bar offset. The plastic neutral axis splits the yield force in half; z is the distance between the two tee centroids and is the lever arm of the axial force couple.
Formula 3 — Moment strength at the opening
$$M_m = \min(P_{y,t}, P_{y,b})\,z \qquad P = M_u / z$$What it means: With no shear the opening can carry the moment by compression in one tee and tension in the other. P is the axial force each tee must carry at the demand moment.
Formula 4 — Four-hinge shear strength with P–M interaction
$$V_i(P) = \min\!\left(\frac{2M_{p,i}(1 - P/P_{y,i})}{a_o},\ V_{p,i}\right) \qquad V_m(P) = V_t + V_b$$What it means: Each tee has two plastic hinges, one at each end of the opening, so its shear strength is 2Mp/ao. The axial force P uses up part of Mp. The linear reduction is conservative because the true interaction surface is convex.
Formula 5 — M–V interaction DCR
$$\text{DCR}_{MV} = 1/s_{max} \quad\text{where } s_{max} = \max\{s: sV_u \le \phi_v V_m(P_n),\ P_n = sM_u/(\phi_b z) \le P_{y,min}\}$$What it means: The demand point (Mu, Vu) is scaled outward along a ray until it meets the design envelope shown in the results. A DCR of 1.0 means the demand sits exactly on the envelope.
Formula 6 — Vierendeel P–M check per tee
$$V_i = V_u\frac{I_i}{I_t + I_b} \qquad M_{v,i} = \frac{V_i a_o}{2} \qquad \frac{P}{\phi_b P_{y,i}} + \frac{M_{v,i}}{\phi_b M_{p,i}} \le 1.0$$What it means: Each tee is fixed at both ends over the opening length, so the end moment is Viao/2. The shear is split by elastic stiffness, which is more conservative than the plastic mechanism when the two tees differ.
Formula 7 — Shear checks
$$V_p = 0.6F_y(d - 2t_f)t_w \qquad V_u \le \tfrac{2}{3}\phi_v V_p \qquad V_{p,i} = 0.6F_y\left[t_w(t_i - t_f) + A_{extra}\right]$$What it means: Tee shear uses only the clear web between the flange and the opening edge. Reinforcement is not credited unless you enter Aextra. The 2/3 overall limit should be confirmed against DG2.
Formula 8 — Tee-column buckling
$$\frac{KL}{r} = \frac{1.2a_o}{r_y} \qquad P_c = \phi_c F_{cr} A \qquad \text{DCR} = P/P_c$$What it means: The compression tee is treated as a short column of length ao about its weak axis, with Fcr from AISC 360 Chapter E and φc = 0.90. K = 1.2 is an assumption of this tool. Bars count only when they are on both sides of the web.
Formula 9 — Compactness
$$\frac{b_f}{2t_f} \le 0.38\sqrt{E/F_y} \qquad \frac{b_R}{t_R} \le 0.38\sqrt{E/F_y}$$What it means: For A992 steel the limit is 9.15. The plastic capacities assume compact elements.
Formula 10 — Gross-section flexure with LTB
$$M_u \le \phi_b M_n \quad (\text{AISC 360 F2},\ C_b = 1.0)$$What it means: An overall-beam check at the opening location using approximate ry, rts and J computed from the dimensions. It is independent of the opening and is conservative with Cb = 1.0.
Formula 11 — Live-load deflection
$$\delta = \max\left|\iint \frac{M_L}{E I_x}\,dx\,dx\right| + \frac{V_L a_o^3}{12E(I_t + I_b)} \le \frac{L}{360}$$What it means: The beam deflection is found by numerical integration for the chosen supports, uniform load and point loads (service live load only). The opening term is the full local displacement across the opening, added without reduction, so it is conservative. It uses It + Ib, which include any reinforcement, so bars do stiffen the opening region. The global Ix is not increased by the bars, which is a reasonable simplification because the opening is a short length of the span.
8. Understanding Your Results — DCR Colour Code and Verdict
Each check is a Demand-to-Capacity Ratio (DCR); 1.0 means 100% utilisation. Capacities already include φ (LRFD) or 1/Ω (ASD).
| Check | What Governs It | What to Do if FAIL |
|---|---|---|
| Opening size (≤ 0.70d) | Opening too deep for the beam. | Reduce the opening or choose a deeper beam. |
| Aspect ratio ao/ho (advisory) | Long, narrow opening. | Shorten the opening or split it. |
| Edge distance | Opening edge closer than d to either support. | Relocate; reinforcement does not cure this. |
| Overall shear (2/3 φVp) | High-shear zone. | Move toward midspan or choose a heavier beam. |
| M–V interaction | Combined shear and moment on the tees. | Add flat bars or reposition. |
| Vierendeel P–M (top / bottom) | Shear transfer through a long opening plus axial force. | Shorten ao, add bars to the weaker tee, or move. |
| Tee web shear | Shallow tee with thin clear web. | Reduce the opening height or relocate. Crediting reinforcement requires justification. |
| Tee-column buckling | Long opening in a high-moment zone. | Shorten ao, add bars on both sides of the web, or move. |
| Reinforcement Fy ≥ beam Fy | Weaker bar steel than the beam. | Use bar steel at least as strong as the beam. |
| Bar area ≥ 50% of tee web; tee PNA within flange (advisory) | Practice-based flags, not DG2 requirements. They show whether the bar is wide enough to brace the tee web and whether the plastic neutral axis stays in the flange. They are listed as REVIEW and do not change the verdict. | Increase the bar area or reduce it, as appropriate, and apply engineering judgement. |
| Point load over opening | A concentrated load acts within the opening length. | Move the opening or the load. The DG2 distance rule for loads near the opening is not checked. |
| Compactness / bar outstand | Thin flange or wide thin bar. | Use a compact shape; thicken or narrow the bar. |
| Gross flexure / LTB | Long unbraced length. | Add bracing or a heavier section. |
| Deflection (L/360) | Flexible beam or large opening near high shear. | Use a stiffer beam or smaller opening. |
9. Worked Example — W21×57, 30 ft Span
▶ Floor Beam with an HVAC Duct Penetration
Problem
A W21×57 (A992, Fy = 50 ksi) spans 30 ft between reaction points, simply supported, with wD = 1.0 and wL = 1.5 kips/ft and no point loads. A 10 in. × 14 in. rectangular opening is centred at mid-depth, x = 10 ft from the left reaction. Lb = 5 ft. LRFD, US units. The numbers below are the calculator's output for these inputs.
Step 1 — Demands over the opening
$w_u = 1.2(1.0) + 1.6(1.5) = 3.6$ kips/ft. The calculator takes the largest shear and moment at the two ends and the centre of the opening (x = 10 ft ± 7 in.). The shear is greatest at the end nearer the support: $V_u = 54.0 - 3.6(10 - 0.583) = 20.1$ kips. The moment is greatest at the other end: $M_u = 4{,}439$ kip·in (at the centre it is 4,320).
Step 2 — Tees
$t_t = t_b = (21.06 - 10)/2 = 5.53$ in. Each tee: flange $6.555 \times 0.65 = 4.26$ in² plus stem $0.405 \times 4.88 = 1.98$ in², so $A = 6.24$ in², $\bar y = 1.20$ in, $Z_{pl} \approx 6.0$ in³.
$P_y = 50(6.24) = 311.9$ kips; $M_p = 50(6.01) = 300.4$ kip·in; $z = 21.06 - 2(1.20) = 18.66$ in.
Step 3 — Axial force and shear strength
$P = 4{,}439/18.66 = 237.9$ kips, against $\phi_b P_y = 280.7$ kips (85% used). Pure-shear strength of the opening: $V_m(0) = 2 \times 2(300.4)/14 = 85.8$ kips; with P applied, each tee's bending strength is reduced by 85%, so little shear strength remains.
Step 4 — Vierendeel check
$V_i = 20.1/2 = 10.05$ kips per tee; $M_{v,i} = 10.05(14)/2 = 70.4$ kip·in.
$$\frac{237.9}{280.7} + \frac{70.4}{270.4} = 0.848 + 0.260 = 1.108$$
Step 5 — Options
Move the opening: at x = 15 ft (midspan) the shear over the opening is only 2.1 kips, Mu = 4,860 kip·in and the governing DCR is 0.955 (Vierendeel / M–V). The position sweep finds this as its lowest value, so for this beam and opening midspan is the best location.
Reinforce: with 2 in. × 1/2 in. flat bars on both sides of the web at the top and bottom edges (1/2 in. from the edge), Mpt rises to about 723 kip·in, Py to 412 kips and z becomes 16.9 in. The M–V DCR falls to 0.82 and tee-column buckling to 0.71. The bar area (2.0 in²) is twice the 50% advisory minimum (0.99 in²), and the tee's plastic neutral axis stays inside the flange (0.63 in. against a flange thickness of 0.65 in.), which leaves the advisory flag at 0.97.
Circular comparison: a 12 in. circular opening at the same position gives an equivalent rectangle of 12 × 10.8 in. unreinforced (DCR 1.16, fails) and 12 × 5.4 in. reinforced (DCR 0.81).
10. Common Mistakes
11. Frequently Asked Questions
DG2 limits the opening depth to about 70% of the beam depth. For a W21×57 (d = 21.06 in.) that is 14.7 in. There is no hard limit on length, but ao/ho above about 3 is flagged. The clear distance from the opening edge to each support must be at least d (about 1.75 ft here). Other standards (for example Eurocode-based guidance, which allows deeper circular openings) use different limits; this tool does not.
It depends on the governing check. Near supports the shear is high and the moment low; at midspan the shear is zero and the axial force in the tees is highest. The sensitivity panel sweeps the span in 2.5% steps and reports the lowest DCR it finds and where. Always confirm the edge distance and overall shear for the location it suggests.
When any DCR exceeds 1.0 unreinforced. Bars along the opening edge increase the area, axial force capacity and plastic moment of each tee, which improves M–V interaction and Vierendeel strength. Bars are assumed to be fully developed by their welds; the weld design is not performed here.
Shear cannot flow through the missing web, so it is carried by the two tees acting as a small frame. Each tee, fixed at both ends over the opening length ao, develops end moments of Viao/2. In the worked example each tee carries 9 kips, giving 63 kip·in at each end of each tee. That secondary moment combines with the axial force produced by the overall bending moment.
They are converted to an equivalent rectangle. Unreinforced: ho = Do, ao = 0.9Do. Reinforced: ho = Do and ao = 0.45Do, so the aspect ratio is 0.45. The physical diameter is checked against 0.70d.
Enter the distance between the points where the reactions act. If the reaction acts at the vertical line of bolts, use the bolt-line spacing, which is shorter than the centreline spacing of the supporting members. Measure x from the same left reaction point. The program does not apply a built-in adjustment for the supports.
Yes. Enter up to three point loads (dead and live, with position) in addition to any uniform load. The tool computes shear and moment across the opening, so shear that is constant or changes at a point load is captured. A point load acting within the opening length fails. The DG2 limit on the distance from a point load to the edge of an opening is not implemented, so verify it manually.
Yes, locally. The bars increase the stiffness of each tee, and the added deflection across the opening uses It + Ib including the bars. The overall beam deflection uses the unmodified Ix, since the bars act over a short length.
Only the clear web: tw times (tee depth − flange thickness), with 0.6Fy and φv = 0.90. Reinforcement is not included unless you enter an extra area. DG2 does not give a rule for crediting an HSS sleeve or ring through the web, so any credit is the engineer's judgement.
No. It plots and checks its own M–V envelope derived from a four-hinge mechanism with linear P–M interaction. Results may be more or less conservative than DG2 depending on the case. Use it for screening and verify against DG2.
No. It checks isolated openings. Regularly spaced openings need a web-post buckling and web-post shear check that is not included. See AISC Design Guide 31 or SCI P355 and use dedicated software.
No. It assumes non-composite behaviour. Composite beams with web openings need the composite provisions of DG2.
No. It is a preliminary screening tool. Outputs must be reviewed and validated by the licensed structural engineer of record, who takes responsibility for the design.
