Structural Software interview questions

1. A.finite element slab results converge with 0.5 to 1 m mesh, but peak moments at column faces are singularities, so design uses strip-integrated moments
2. B.Y is vertical by default, so self-weight is applied as SELFWEIGHT Y −1 and lateral loads act along X and Z
3. C.seismic combos apply 100 percent of earthquake in one direction with 30 percent in the perpendicular direction, so EX ± 0.3 EY and EY ± 0.3 EX are both generated
4. D.floor modelled as infinitely stiff in its own plane so every node on the level shares two translations and one rotation, appropriate for solid slabs without large openings

Answer + AI explanation with Pro

1. A.STAAD.Pro global axes
2. B.Result sanity checks
3. C.P-delta analysis
4. D.Slab mesh and design strips

Answer + AI explanation with Pro

1. A.STAAD.Pro global axes — enough modes must be included to capture at least 90 percent of total seismic mass in each direction, which Ritz vectors reach with fewer modes than eigenvectors
2. B.STAAD.Pro global axes — floor modelled as infinitely stiff in its own plane so every node on the level shares two translations and one rotation, appropriate for solid slabs without large openings
3. C.STAAD.Pro global axes — seismic combos apply 100 percent of earthquake in one direction with 30 percent in the perpendicular direction, so EX ± 0.3 EY and EY ± 0.3 EX are both generated
4. D.STAAD.Pro global axes — Y is vertical by default, so self-weight is applied as SELFWEIGHT Y −1 and lateral loads act along X and Z

Answer + AI explanation with Pro

1. A.floor modelled as infinitely stiff in its own plane so every node on the level shares two translations and one rotation, appropriate for solid slabs without large openings
2. B.seismic combos apply 100 percent of earthquake in one direction with 30 percent in the perpendicular direction, so EX ± 0.3 EY and EY ± 0.3 EX are both generated
3. C.enough modes must be included to capture at least 90 percent of total seismic mass in each direction, which Ritz vectors reach with fewer modes than eigenvectors
4. D.finite element slab results converge with 0.5 to 1 m mesh, but peak moments at column faces are singularities, so design uses strip-integrated moments

Answer + AI explanation with Pro

1. A.P-delta analysis
2. B.Rigid diaphragm
3. C.Modal mass participation
4. D.Result sanity checks

Answer + AI explanation with Pro

1. A.Rigid diaphragm — enough modes must be included to capture at least 90 percent of total seismic mass in each direction, which Ritz vectors reach with fewer modes than eigenvectors
2. B.Rigid diaphragm — floor modelled as infinitely stiff in its own plane so every node on the level shares two translations and one rotation, appropriate for solid slabs without large openings
3. C.Rigid diaphragm — finite element slab results converge with 0.5 to 1 m mesh, but peak moments at column faces are singularities, so design uses strip-integrated moments
4. D.Rigid diaphragm — Y is vertical by default, so self-weight is applied as SELFWEIGHT Y −1 and lateral loads act along X and Z

Answer + AI explanation with Pro

1. A.second-order analysis in which gravity load acting on the laterally displaced geometry amplifies moments and drifts, run iteratively rather than as a linear solve
2. B.finite element slab results converge with 0.5 to 1 m mesh, but peak moments at column faces are singularities, so design uses strip-integrated moments
3. C.Y is vertical by default, so self-weight is applied as SELFWEIGHT Y −1 and lateral loads act along X and Z
4. D.floor modelled as infinitely stiff in its own plane so every node on the level shares two translations and one rotation, appropriate for solid slabs without large openings

Answer + AI explanation with Pro

1. A.P-delta analysis
2. B.Cracked stiffness modifiers
3. C.STAAD.Pro global axes
4. D.Result sanity checks

Answer + AI explanation with Pro

1. A.P-delta analysis — seismic combos apply 100 percent of earthquake in one direction with 30 percent in the perpendicular direction, so EX ± 0.3 EY and EY ± 0.3 EX are both generated
2. B.P-delta analysis — enough modes must be included to capture at least 90 percent of total seismic mass in each direction, which Ritz vectors reach with fewer modes than eigenvectors
3. C.P-delta analysis — second-order analysis in which gravity load acting on the laterally displaced geometry amplifies moments and drifts, run iteratively rather than as a linear solve
4. D.P-delta analysis — finite element slab results converge with 0.5 to 1 m mesh, but peak moments at column faces are singularities, so design uses strip-integrated moments

Answer + AI explanation with Pro

1. A.seismic combos apply 100 percent of earthquake in one direction with 30 percent in the perpendicular direction, so EX ± 0.3 EY and EY ± 0.3 EX are both generated
2. B.finite element slab results converge with 0.5 to 1 m mesh, but peak moments at column faces are singularities, so design uses strip-integrated moments
3. C.IS 1893:2016 requires RC members analysed with 70 percent of gross moment of inertia for columns and 35 percent for beams, applied as property modifiers
4. D.second-order analysis in which gravity load acting on the laterally displaced geometry amplifies moments and drifts, run iteratively rather than as a linear solve

Answer + AI explanation with Pro

1. A.Orthogonal load combination
2. B.STAAD.Pro global axes
3. C.Cracked stiffness modifiers
4. D.Modal mass participation

Answer + AI explanation with Pro

1. A.Cracked stiffness modifiers — seismic combos apply 100 percent of earthquake in one direction with 30 percent in the perpendicular direction, so EX ± 0.3 EY and EY ± 0.3 EX are both generated
2. B.Cracked stiffness modifiers — IS 1893:2016 requires RC members analysed with 70 percent of gross moment of inertia for columns and 35 percent for beams, applied as property modifiers
3. C.Cracked stiffness modifiers — enough modes must be included to capture at least 90 percent of total seismic mass in each direction, which Ritz vectors reach with fewer modes than eigenvectors
4. D.Cracked stiffness modifiers — sum of vertical reactions must equal applied gravity load, storey drift must stay within 0.004 of storey height and unity ratios and mode shapes must look physical

Answer + AI explanation with Pro

1. A.enough modes must be included to capture at least 90 percent of total seismic mass in each direction, which Ritz vectors reach with fewer modes than eigenvectors
2. B.IS 1893:2016 requires RC members analysed with 70 percent of gross moment of inertia for columns and 35 percent for beams, applied as property modifiers
3. C.seismic combos apply 100 percent of earthquake in one direction with 30 percent in the perpendicular direction, so EX ± 0.3 EY and EY ± 0.3 EX are both generated
4. D.floor modelled as infinitely stiff in its own plane so every node on the level shares two translations and one rotation, appropriate for solid slabs without large openings

Answer + AI explanation with Pro

1. A.Modal mass participation
2. B.STAAD.Pro global axes
3. C.Cracked stiffness modifiers
4. D.Rigid diaphragm

Answer + AI explanation with Pro

1. A.Modal mass participation — second-order analysis in which gravity load acting on the laterally displaced geometry amplifies moments and drifts, run iteratively rather than as a linear solve
2. B.Modal mass participation — enough modes must be included to capture at least 90 percent of total seismic mass in each direction, which Ritz vectors reach with fewer modes than eigenvectors
3. C.Modal mass participation — floor modelled as infinitely stiff in its own plane so every node on the level shares two translations and one rotation, appropriate for solid slabs without large openings
4. D.Modal mass participation — IS 1893:2016 requires RC members analysed with 70 percent of gross moment of inertia for columns and 35 percent for beams, applied as property modifiers

Answer + AI explanation with Pro

1. A.Y is vertical by default, so self-weight is applied as SELFWEIGHT Y −1 and lateral loads act along X and Z
2. B.seismic combos apply 100 percent of earthquake in one direction with 30 percent in the perpendicular direction, so EX ± 0.3 EY and EY ± 0.3 EX are both generated
3. C.floor modelled as infinitely stiff in its own plane so every node on the level shares two translations and one rotation, appropriate for solid slabs without large openings
4. D.IS 1893:2016 requires RC members analysed with 70 percent of gross moment of inertia for columns and 35 percent for beams, applied as property modifiers

Answer + AI explanation with Pro

1. A.Modal mass participation
2. B.Slab mesh and design strips
3. C.Orthogonal load combination
4. D.Result sanity checks

Answer + AI explanation with Pro

1. A.Orthogonal load combination — Y is vertical by default, so self-weight is applied as SELFWEIGHT Y −1 and lateral loads act along X and Z
2. B.Orthogonal load combination — seismic combos apply 100 percent of earthquake in one direction with 30 percent in the perpendicular direction, so EX ± 0.3 EY and EY ± 0.3 EX are both generated
3. C.Orthogonal load combination — enough modes must be included to capture at least 90 percent of total seismic mass in each direction, which Ritz vectors reach with fewer modes than eigenvectors
4. D.Orthogonal load combination — floor modelled as infinitely stiff in its own plane so every node on the level shares two translations and one rotation, appropriate for solid slabs without large openings

Answer + AI explanation with Pro

1. A.second-order analysis in which gravity load acting on the laterally displaced geometry amplifies moments and drifts, run iteratively rather than as a linear solve
2. B.floor modelled as infinitely stiff in its own plane so every node on the level shares two translations and one rotation, appropriate for solid slabs without large openings
3. C.finite element slab results converge with 0.5 to 1 m mesh, but peak moments at column faces are singularities, so design uses strip-integrated moments
4. D.IS 1893:2016 requires RC members analysed with 70 percent of gross moment of inertia for columns and 35 percent for beams, applied as property modifiers

Answer + AI explanation with Pro

1. A.Slab mesh and design strips
2. B.STAAD.Pro global axes
3. C.Modal mass participation
4. D.Result sanity checks

Answer + AI explanation with Pro

1. A.Slab mesh and design strips — finite element slab results converge with 0.5 to 1 m mesh, but peak moments at column faces are singularities, so design uses strip-integrated moments
2. B.Slab mesh and design strips — enough modes must be included to capture at least 90 percent of total seismic mass in each direction, which Ritz vectors reach with fewer modes than eigenvectors
3. C.Slab mesh and design strips — seismic combos apply 100 percent of earthquake in one direction with 30 percent in the perpendicular direction, so EX ± 0.3 EY and EY ± 0.3 EX are both generated
4. D.Slab mesh and design strips — IS 1893:2016 requires RC members analysed with 70 percent of gross moment of inertia for columns and 35 percent for beams, applied as property modifiers

Answer + AI explanation with Pro

1. A.seismic combos apply 100 percent of earthquake in one direction with 30 percent in the perpendicular direction, so EX ± 0.3 EY and EY ± 0.3 EX are both generated
2. B.sum of vertical reactions must equal applied gravity load, storey drift must stay within 0.004 of storey height and unity ratios and mode shapes must look physical
3. C.second-order analysis in which gravity load acting on the laterally displaced geometry amplifies moments and drifts, run iteratively rather than as a linear solve
4. D.floor modelled as infinitely stiff in its own plane so every node on the level shares two translations and one rotation, appropriate for solid slabs without large openings

Answer + AI explanation with Pro

1. A.P-delta analysis
2. B.Slab mesh and design strips
3. C.Cracked stiffness modifiers
4. D.Result sanity checks

Answer + AI explanation with Pro

1. A.Result sanity checks — sum of vertical reactions must equal applied gravity load, storey drift must stay within 0.004 of storey height and unity ratios and mode shapes must look physical
2. B.Result sanity checks — finite element slab results converge with 0.5 to 1 m mesh, but peak moments at column faces are singularities, so design uses strip-integrated moments
3. C.Result sanity checks — IS 1893:2016 requires RC members analysed with 70 percent of gross moment of inertia for columns and 35 percent for beams, applied as property modifiers
4. D.Result sanity checks — enough modes must be included to capture at least 90 percent of total seismic mass in each direction, which Ritz vectors reach with fewer modes than eigenvectors

Answer + AI explanation with Pro