Inelastic Flexural Behaviour and Ductility Characteristics of Steel-Encased Composite Beams Incorporating Normal and High-Strength Concrete Under Out-of-Plane Actions: Nonlinear Finite Element Investigation

Muna Saad Ibrahim Alkarkoosh; Mohammed A. Radi; Zainab Oday Hanoosh

doi:10.2478/cee-2027-0023

Inelastic Flexural Behaviour and Ductility Characteristics of Steel-Encased Composite Beams Incorporating Normal and High-Strength Concrete Under Out-of-Plane Actions: Nonlinear Finite Element Investigation

Civil and Environmental Engineering

AHEAD OF PRINT

By: Muna Saad Ibrahim Alkarkoosh, Mohammed A. Radi and Zainab Oday Hanoosh

Open Access

|Oct 2026

Figures & Tables

Beam with out-of-plane parts applications

Plastic damage curve of ordinary concrete under uniaxial compression

The finite element model shows the mesh of OPB beams in ANSYS

Table 1:

Verification results include the failure load

SP	Experimental load P_E [kN] By (Mohsin et al. 2021)	Numerical load P_N [kN] by (Albegmprli et al. 2025)	Numerical load P_N (kN)	Matching (1) of P_E and P_N	Matching (2) of P_E and P_N
NSC-1OP	369.2	364.77	376.42	101.96%	103.19%
HSC-1OP	385.99	363.99	394.54	102.22%	108.39%
HSC-1OPT	460.49	467.40	484.87	105.29%	103.74%

Table 2:

Verification results include the maximum displacement

SP	Experimental Disp. ∆_E (mm) (Mohsin et al. 2021)	Numerical Disp. ∆_N (mm) (Albegmprli et al. 2025)	Numerical Disp. ∆_N (mm	Matching (2) of ∆_E and ∆_N	Matching (2) of ∆_E and ∆_N
NSC-1OP	61.21	54.97	53.11	91.67%	96.62%
HSC-1OP	51.22	51.15	47.53	92.80%	92.92%
HSC-1OPT	49.62	48.63	46.21	93.13%	95.02%

Comparison between the experimental and simulated OPB beams

Table 3:

Details of specimens

ID	Concrete Type	f′c (N/mm²)	Fr (N/mm²)	βt	βc	E_C (N/mm²)	OPBs Number
BOPB1	NSC	40	3.92	0.213	0.718	29.73 × 10³	Linear Section
NSC-OPB2	NSC	40	3.92	0.327	0.841	29.73 × 10³	Two segments
NSC-OPB3	NSC	40	3.92	0.294	0.653	29.73 × 10³	Three segments
NSC-OPB4	NSC	40	3.92	0.221	0.709	29.73 × 10³	Four segments
NSC-OPB2C	NSC	40	3.92	0.341	0.829	29.73 × 10³	Two segments
NSC-OPB3C	NSC	40	3.92	0.259	0.665	29.73 × 10³	Three segments
NSC-OPB4C	NSC	40	3.92	0.276	0.691	29.73 × 10³	Four segments
HSC-OPB2	HSC	70	5.54	0.237	0.734	31.35 × 10³	Two segments
HSC-OPB3	HSC	70	5.54	0.331	0.673	31.35 × 10³	Three segments
HSC-OPB4	HSC	70	5.54	0.297	0.805	31.35 × 10³	Four segments
HSC-OPB2C	HSC	70	5.54	0.289	0.847	31.35 × 10³	Two segments
HSC-OPB3C	HSC	70	5.54	0.266	0.621	31.35 × 10³	Three segments
HSC-OPB4C	HSC	70	5.54	0.323	0.788	31.35 × 10³	Four segments

Table 4:

Results of NSC and HSCOPB

Variable	ID	Yield load (kN)	Yield disp. (mm)	Failure load (kN)	δ corr. To Pu (mm)	ε_max	Von Mises ε_max	Von mises σ_max (MPa)
Series One ref.	BOPB1	184.52	8.92	604.66	30.12	0.00373	0.019236	405.19
NSC	NSC-OPB2	138.97	10.17	379.41	42.46	0.01981	0.057806	401.19
	NSC-OPB3	127.56	8.56	289.37	33.36	0.02252	0.067392	401.65
	NSC-OPB4	126.18	8.44	229.14	21.44	0.02199	0.017716	180.66
Composite NSC	NSC-OPB2C	154.95	13.80	638.93	38.77	0.0149	0.04512	426.51
	NSC-OPB3C	152.43	8.88	441.00	28.46	0.01637	0.048753	412.24
	NSC-OPB4C	128.07	9.45	304.30	15.84	0.01598	0.039801	384.02
Series Two ref.	HSC-BOPB1	188.00	9.20	712.89	27.84	0.00351	0.018304	412.68
HSC	HSC-OPB2	200.67	11.15	586.57	38.78	0.01894	0.055671	397.85
	HSC-OPB3	168.77	7.43	430.29	22.36	0.02131	0.064788	403.13
	HSC-OPB4	142.94	8.16	353.79	21.44	0.02011	0.015602	176.54
Composite HSC with section	HSC-OPB2C	225.36	11.90	730.86	36.98	0.01387	0.041782	434.76
	HSC-OPB3C	193.07	10.59	542.60	28.63	0.01555	0.045501	418.23
	HSC-OPB4C	155.52	7.03	418.18	17.61	0.01512	0.03634	389.56

Table 4:

Results percentages of NSC and HSCOPB

ID	Yield load changing percentage	Yield disp. changing percentage	Failure load: changing percentage	δ changing percentage	ε_max changing percentage	Von mises ε_max changing percentage	Von mises σ_max changing percentage
BOPB1	-	-	-	-	-	-	-
NSC-OPB2	−24.69%	14.01%	−37.25%	43.79%	431.13%	200.51%	−0.99%
NSC-OPB3	−30.87%	−4.04%	−52.14%	12.97%	503.97%	250.34%	−0.87%
NSC-OPB4	−31.62%	−5.38%	−62.10%	−27.40%	489.62%	−7.90%	−55.41%
NSC-OPB2C	−16.02%	54.71%	5.67%	31.28%	299.65%	134.56%	5.26%
NSC-OPB3C	−17.39%	−0.45%	−27.07%	−3.62%	339.10%	153.45%	1.74%
NSC-OPB4C	−30.59%	5.94%	−49.67%	−46.36%	328.53%	106.91%	−5.23%
HSC-BOPB1	−	−	−	−	−	−	−
HSC-OPB2	6.74%	21.20%	−17.72%	39.30%	439.29%	204.15%	−3.59%
HSC-OPB3	−10.23%	−19.24%	−39.64%	−19.68%	506.72%	253.96%	−2.32%
HSC-OPB4	−23.97%	−11.30%	−50.37%	−22.99%	472.69%	−14.76%	−57.22%
HSC-OPB2C	19.87%	29.35%	2.52%	32.83%	294.99%	128.27%	5.35%
HSC-OPB3C	2.70%	15.11%	−23.89%	2.84%	342.65%	148.59%	1.34%
HSC-OPB4C	−17.27%	−23.59%	−41.34%	−36.75%	330.64%	98.54%	−5.60%

Cracking and ultimate loads of NSC Non-Composite OPB beams

Cracking and ultimate loads of NSC Composite OPB beams

Cracking and ultimate loads of HSC non-composite OPB beams

Cracking and ultimate loads of HSC composite OPB beams

Load-deflection relationship of NSC OPB beams

Load-deflection relationship of HSC OPB beams

Table 5:

Results of ductility indices, initial stiffness, and toughness

Variable	ID	Ductility index	Ki [kN/mm]	Toughness [kN.mm]
Series one ref.	BOPB1	3.31	20.69	8929.60
NSC	NSC-OPB2	4.17	13.65	8055.30
	NSC-OPB3	3.90	14.89	4814.40
	NSC-OPB4	2.54	14.94	2457.80
Composite NSC	NSC-OPB2C	4.63	11.22	11786.00
	NSC-OPB3C	2.91	17.71	9004.20
	NSC-OPB4C	3.25	13.56	5856.70
Series Two Ref.	HSC-BOPB1	3.26	20.43	10693.40
HSC	HSC-OPB2	4.28	20.07	9336.90
	HSC-OPB3	3.01	20.89	6906.60
	HSC-OPB4	2.45	16.95	3117.80
Composite HSC with section	HSC-OPB2C	4.03	25.10	12752.10
	HSC-OPB3C	3.28	27.51	8048.70
	HSC-OPB4C	2.51	22.12	3693.10

Cracking mode, stress distribution, and failure mechanism of the NSC-OPB2C beam

Cracking mode, stress distribution, and failure mechanism of HSC-OPB beam

References

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Articles in this issue

DOI: https://doi.org/10.2478/cee-2027-0023 | Journal eISSN: 2199-6512 (formerly 1336-5835) | Journal ISSN: 1336-5835

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Language: English

Submitted on: May 24, 2026

Accepted on: Jul 24, 2026

Published on: Oct 16, 2026

Published by: University of Žilina

In partnership with: Paradigm Publishing Services

Publication frequency: 4 issues per year

Keywords:

Inelastic flexural behaviour,

Out-of-plane parts,

Ductility,

Energy absorption,

Shear-torsional failure

Related subjects:

Business and economics,

Business management,

Industries,

Environmental management

© 2026 Muna Saad Ibrahim Alkarkoosh, Mohammed A. Radi, Zainab Oday Hanoosh, published by University of Žilina
This work is licensed under the Creative Commons Attribution 4.0 License.

AHEAD OF PRINT

Inelastic Flexural Behaviour and Ductility Characteristics of Steel-Encased Composite Beams Incorporating Normal and High-Strength Concrete Under Out-of-Plane Actions: Nonlinear Finite Element Investigation

Figures & Tables

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