nach oben

Erschienen in:

Open Access 2023 | OriginalPaper | Buchkapitel

Investigation of Web Hole Effects on Capacities of Cold-Formed Steel Channel Members

verfasst von : Ngoc Hieu Pham

Erschienen in: Proceedings of the 2nd International Conference on Innovative Solutions in Hydropower Engineering and Civil Engineering

Verlag: Springer Nature Singapore

Aktivieren Sie unsere intelligente Suche, um passende Fachinhalte oder Patente zu finden.

search-config

KI-gestützte Suche

Patentsuche

Aus

Abstract

Cold-formed steel structures have been widely applied in structural buildings with advantages in manufacturing, transportation and assembly. Holes can be pre-punched in the sectional members to allow technical pipes to go throughout such as electricity, water or ventilation. This affects the capacities of these such members which have been considered in the design standards in America or Australia/New Zealand. The paper, therefore, investigates the effects of web holes on the capacities of cold-formed steel channel members under compression or bending. Their capacities can be determined according to the American Specification AISI S100-16. The investigated results are the base for analysing the effects of web hole dimensions on the behaviors and capacities of cold-formed steel channel members. It was found that the capacity reductions were obtained for compressive members with the increase in hole sizes, but the flexural capacities were noticeable increase with the increase in the hole heights.

1 Introduction

Cold-formed steel members have been progressively applied in structural buildings due to their advantages compared to traditional steel structures [1]. Channel sections are the common products worldwide for many decades [2]. Holes are pre-punched in the webs of such members to allow the technical pipes such as water and electricity to go throughout with the variation of hole shapes. The presence of holes has been demonstrated to reduce the capacities of these cold-formed steel members and has been considered in the American and Australian/New Zealand design standards ([3, 4]). According to these standards, a new method has been introduced in the design of cold-formed steel members namely the Direct Strength Method (DSM) which has been illustrated to be innovative compared to the traditional design method—the Effective Width Method [5]. The DSM will be used for the investigation in this paper.

The DSM allows the designer to directly predict the capacities of cold-formed steel members based on the determination of elastic buckling loads. These buckling loads can be provided by utilising several software programs for buckling analysis of cold-formed steel sections such as CUFSM [6] or THIN-WALL-2 [7]. The application of these software programs in the design is reported in the works of Pham [8] or Pham and Vu [9]. For cold-formed steel sections with perforations, the determination of elastic buckling loads was studied and subsequently proposed by Moen and Schafer ([10‐16]). Their research results were the base for the development of a module software program CUFSM funded by the American Iron and Steel Institute ([17, 18]). This module software program will be introduced and applied in the buckling analysis of cold-formed steel sections with perforations in this paper.

The paper presents the application of the DSM in the determination of capacities of cold-formed steel channel members with perforations according to the American Specification AISI S100-16 [3]. The rectangular hole shapes are considered and are arranged evenly with the variation of the hole sizes. The hole heights vary from 0.2 to 0.8 times of the investigated sectional depths whereas their lengths are from 0.5 to 2.0 times of the depths. The material properties are regulated in the American Specification [3]. The boundary conditions are varied to obtain different buckling modes of the investigated cold-formed steel members under compression or bending. The investigated results will be used to analyse the influence of hole sizes on the capacities of cold-formed steel channel members with perforations under compression or bending.

2 Determination of Capacities of Cold-Formed Steel Members Under Compression or Bending According to the American Specification AISI S100-16

The provisions for the design of cold-formed steel members are presented in Chapter E for compression and Chapter F for bending according to the American Specification AISI S100-16 [3]. The DSM for the design of cold-formed steel members is presented in this paper.

2.1 Member in Compression

The nominal axial strength (P_n) is the least of three following strength values including global buckling strength (P_ne), local buckling strength (P_nl), and distortional buckling strength (P_nd).

Global Buckling Strength (P_ne)

$$ P_{ne} = \left( {0.658^{{\lambda_{c}^{2} }} } \right)P_{y} \quad {\text{if}}\,\lambda_{C} \le {1}.{5} $$

(1)

$$ P_{ne} = \left( {\frac{0.877}{{\lambda_{c}^{2} }}} \right)P_{y} \quad {\text{if}}\,\lambda_{C} > {1}.{5} $$

(2)

where $\lambda_{c} = \sqrt {P_{y} /P_{cre} }$;

P _y

Is the yield strength of the gross section;

P _cre

Is the elastic global buckling strength, is taken as the smaller of the following values.

$$ P_{ey} = \frac{{\pi^{2} EI_{y} }}{{(K_{y} L)^{2} }} $$

(3)

$$ \begin{aligned} P_{exz} & = \frac{1}{2\beta }\left[ {(P_{{{\text{ex}}}} + P_{t} ) - \sqrt {(P_{{{\text{ex}}}} + P_{t} )^{2} - 4\beta P_{{{\text{ex}}}} P_{t} } } \right] \\ P_{{{\text{ex}}}} & = \frac{{\pi^{2} EI_{x} }}{{(K_{x} L)^{2} }};P_{t} = \frac{1}{{r_{o}^{2} }}\left( {GJ + \frac{{\pi^{2} EC_{{\text{w}}} }}{{{\text{(K}}_{{\text{t}}} {\text{L)}}^{{2}} }}} \right);r_{o} = \sqrt {x_{o}^{2} + y_{o}^{2} + \frac{{I_{x} + I_{y} }}{{A_{g} }}} \\ \end{aligned} $$

(4)

The sectional properties (I_x, I_y, J, A_g, x_o, y_o, r_o) are determined on the basis of the gross-section. These properties for perforated sections can be determined using the “weighted average” approach as presented in table 2.3.2-1 of the specification [3] based on the ratio between the segment length of the gross-section and the net section, as follows:

$$\begin{aligned} I_{avg} & = \frac{{I_{g} L_{g} + I_{net} L_{net} }}{L};J_{avg} = \frac{{J_{g} L_{g} + J_{net} L_{net} }}{L} \\ r_{o,avg} & = \sqrt {x_{o,avg}^{2} + y_{o,avg}^{2} + \frac{{I_{x,avg} + I_{y,avg} }}{{A_{avg} }}} ;A_{avg} = \frac{{A_{g} L_{g} + A_{net} L_{net} }}{L} \\ x_{o,avg} & = \frac{{x_{o,g} L_{g} + x_{o,net} L_{net} }}{L};y_{o,avg} = \frac{{y_{o,g} L_{g} + y_{o,net} L_{net} }}{L} \\ \end{aligned}$$

C_w,net is the net warping constant assuming the hole height h_hole* as determined in Eq. (5), where h_hole is the actual hole height and D is the sectional depth

$$ h_{hole*} = h_{hole} + \frac{1}{2}(H - h_{hole} )\left( {\frac{{h_{hole} }}{H}} \right)^{0,2} $$

(5)

Local Buckling Strength (P_nl)

$$ P_{nl} = \left\{ {\begin{array}{*{20}c} {P_{ne} } & {for \, \lambda_{{\text{l}}} \le 0.776} \\ {\left[ {1 - 0.15\left( {\frac{{P_{crl} }}{{P_{ne} }}} \right)^{0.4} } \right]\left( {\frac{{P_{crl} }}{{P_{ne} }}} \right)^{0.4} P_{y} } & {for \, \lambda_{{\text{l}}} > 0.776} \\ \end{array} } \right. \, $$

(6)

where λ_l is the slenderness factor for local buckling, $\lambda_{l} = \sqrt {P_{ne} /P_{crl} }$;

P_crl is the elastic local buckling load of the gross section or perforated section that can be determined using elastic buckling analyses.

Distortional Buckling Strength (P_nd)

$$ P_{nd} = \left\{ {\begin{array}{*{20}l} {P_{y} } \hfill & {for \, \lambda_{{\text{d}}} \le 0.561} \hfill \\ {\left[ {1 - 0.25\left( {\frac{{P_{crd} }}{{P_{y} }}} \right)^{0.6} } \right]\left( {\frac{{P_{crd} }}{{P_{y} }}} \right)^{0.6} P_{y} } \hfill & {for \, \lambda_{{\text{d}}} > 0.561} \hfill \\ \end{array} } \right. $$

(7)

where λ_d is the slenderness factor for distortional buckling, $\lambda_{d} = \sqrt {P_{y} /P_{crd} }$;

P_crd is the elastic distortional buckling load of the gross section or perforated section that can be determined using elastic buckling analyses. For the perforated section, if λ_d ≤ λ_d2, where λ_d2 is determined as in Eq. (10) then:

$$ P_{nd} = \left\{ {\begin{array}{*{20}l} {P_{ynet} } \hfill & {for \, \lambda_{{\text{d}}} \le \lambda_{{{\text{d1}}}} } \hfill \\ {P_{ynet} - \left( {\frac{{P_{ynet} - P_{d2} }}{{\lambda_{d2} - \lambda_{d1} }}} \right)\left( {\lambda_{d} - \lambda_{d1} } \right)} \hfill & {for \, \lambda_{{{\text{d1}}}} < \lambda_{{\text{d}}} \le \lambda_{{{\text{d2}}}} } \hfill \\ \end{array} } \right. $$

(8)

P _ynet

Is the axial yield strengths of the net section;

λ _d1 , λ _d2

Are the slenderness factors of distortional buckling;

P _d2

Is the nominal axial strength of distortional buckling at λ_d2.

$$ \lambda_{d1} = 0.561\left( {\frac{{P_{ynet} }}{{P_{y} }}} \right) $$

(9)

$$ \lambda_{d2} = 0.561\left[ {14\left( {\frac{{P_{y} }}{{P_{ynet} }}} \right)^{0.4} - 13} \right] $$

(10)

$$ P_{d2} = \left[ {1 - 0.25\left( {\frac{1}{{\lambda_{d2} }}} \right)^{1.2} } \right]\left( {\frac{1}{{\lambda_{d2} }}} \right)^{1.2} P_{y} $$

(11)

2.2 Member in Flexure

The nominal moment of a beam (M_n) is the least of three values including global buckling moment (M_ne), local buckling moment (M_nl), and distortional buckling moment (M_nd).

Global Buckling Moment (M_ne)

$$ M_{ne} = M_{y} \quad {\text{if}}\,M_{cre} \ge \, 2.78M_{y} $$

(12)

$$ M_{ne} = \frac{10}{9}\left( {1 - \frac{{10M_{y} }}{{36M_{cre} }}} \right)M_{y} \quad {\text{if}}\,0.56F_{y} < \, M_{cre} < \, 2.78 \, M_{y} $$

(13)

$$ M_{ne} = M_{cre} \quad {\text{if}}\,M_{cre} \le \, 0.56M_{y} $$

(14)

where M_y is the yield moment of the gross sections; M_cre is the elastic global buckling moment that can be determined as follows:

$$ M_{cre} = \frac{\pi }{{K_{y} L}}\sqrt {EI_{y} \left( {GJ + \frac{{\pi^{2} EC_{{\text{w}}} }}{{{\text{(K}}_{{\text{t}}} {\text{L)}}^{{2}} }}} \right)} $$

The sectional properties are defined and determined as presented in Sect. 2.1 for the gross section and the perforated section.

Local Buckling Moment (M_nl)

$$ M_{nl} = \left\{ {\begin{array}{*{20}l} {M_{ne} } \hfill & {for \, \lambda_{{\text{l}}} \le 0.776} \hfill \\ {\left[ {1 - 0.15\left( {\frac{{M_{crl} }}{{M_{ne} }}} \right)^{0.4} } \right]\left( {\frac{{M_{crl} }}{{M_{ne} }}} \right)^{0.4} M_{y} } \hfill & {for \, \lambda_{{\text{l}}} > 0.776} \hfill \\ \end{array} } \right. $$

(15)

where λ_l is the slenderness factor for local buckling, $\lambda_{l} = \sqrt {M_{ne} /M_{crl} }$;

M_crl is the elastic local buckling moment of the gross section or perforated section that can be determined using elastic buckling analyses.

Distortional Buckling Moment (M_nd)

$$ M_{nd} = \left\{ {\begin{array}{*{20}l} {M_{y} } \hfill & {for\,\lambda_{{\text{d}}} \le 0.673} \hfill \\ {\left[ {1 - 0.22\left( {\frac{{M_{crd} }}{{M_{y} }}} \right)^{0.5} } \right]\left( {\frac{{M_{crd} }}{{M_{y} }}} \right)^{0.5} M_{y} } \hfill & {for\,\lambda_{{\text{d}}} > 0.673} \hfill \\ \end{array} } \right. \, $$

(16)

where λ_d is the slenderness factor for distortional buckling, $\lambda_{d} = \sqrt {M_{y} /M_{crd} }$;

M_crd is the elastic distortional buckling moment of the gross section or perforated section that can be determined using elastic buckling analyses. For the perforated section, if λ_d ≤ λ_d2, where λ_d2 is determined as in Eq. (19) then:

$$ M_{nd} = \left\{ {\begin{array}{*{20}l} {M_{ynet} } \hfill & {for\,\lambda_{{\text{d}}} \le \lambda_{{{\text{d1}}}} } \hfill \\ {M_{ynet} - \left( {\frac{{M_{ynet} - M_{d2} }}{{\lambda_{d2} - \lambda_{d1} }}} \right)\left( {\lambda_{d} - \lambda_{d1} } \right)} \hfill & {for\,\lambda_{{{\text{d1}}}} < \lambda_{{\text{d}}} \le \lambda_{{{\text{d2}}}} } \hfill \\ \end{array} } \right. $$

(17)

M_ynet

Is the yield moment of the net section;

λ_d1 and λ_d2

Are the slenderness factors of distortional buckling;

M_d2

Is the nominal moment of distortional buckling at λ_d2.

$$ \lambda_{d1} = 0.673\left( {\frac{{M_{ynet} }}{{M_{y} }}} \right)^{3} $$

(18)

$$ \lambda_{d2} = 0.673\left[ {1.7\left( {\frac{{M_{y} }}{{M_{ynet} }}} \right)^{2.7} - 0.7} \right] $$

(19)

$$ M_{d2} = \left[ {1 - 0.22\left( {\frac{1}{{\lambda_{d2} }}} \right)} \right]\left( {\frac{1}{{\lambda_{d2} }}} \right)M_{y} $$

(20)

3 Elastic Buckling Analyses for Cold-Formed Steel Channel Members with Perforations

Elastic buckling analysis is a compulsory step to apply the DSM in the determination of capacities of cold-formed steel members. Section C20015 taken from the commercial sections is selected for the investigation, as illustrated in Fig. 1, where “C” indicates the channel section; the nominal dimensions include the depth D = 203 mm, the width B = 76 mm, the lip length L = 19.5 mm, and the thickness t = 1.5 mm. Rectangular hole shape is considered in this investigation with the hole heights varying from 0.2 to 0.8 times of the sectional depth (D), and the hole lengths varying from 0.5 to 2.0 times of the depth (D).

3.1 Elastic Sectional Buckling Analyses

The elastic sectional buckling analyses are carried out with the support of the module software program CUFSM [18]. This program requires simple input and directly provides output results including the local buckling and distortional buckling loads of both gross-section and perforated sections, as illustrated in Fig. 2. It was found that elastic local buckling loads only depend on the hole heights whereas they are hole lengths for distortional buckling loads [10]. The material properties regulated in the American Specification [3] include the strength F_y = 345 MPa, and Young’s modulus E = 203,400 MPa. The elastic buckling loads, therefore, are determined and reported in Table 1.

Table 1

Elastic buckling loads of C20015 section

Hole dimensions		Local buckling		Distortional buckling
Hole dimensions		Compression (kN)	Flexure (kNm)	Compression (kN)	Flexure (kNm)
No hole		33.01	10.49	76.67	10.31
h_hole	0.2D	31.93	5.65
	0.5D	66.47	8.01
	0.8D	114	10.98
L_hole	0.5D			71.55	9.71
	D			66.29	9.04
	1.5D			60.85	8.32
	2D			55.18	7.53

Table 1 shows that the elastic loads are seen as an increasing trend for local buckling modes, and the opposite trend is obtained for distortional buckling modes when the hole sizes increase. The distortional buckling loads of perforated sections are always less than those of the gross section. Meanwhile, the local buckling loads of the net section are even higher than those of this gross section (see the hole heights of 0.5D and 0.8D for compression, or 0.8D for bending). This means that local buckling modes will occur at the net section for small hole heights and at the gross section areas between holes for large hole heights. The reason for this has been explained in previous studies [19]. Therefore, the elastic local buckling loads (P_crl, M_crl) of the perforated sections can be taken as the smaller of these load values of the gross section and the net section for the design.

3.2 Global Buckling Analyses

The C20015 section is chosen for the investigation with the length of 2500 mm. There are 05 symmetrical and even holes in the web of the investigated section as shown in Fig. 3. The variations of hole sizes have been presented above.

The specimen will be investigated under compression and bending. For compression, two different boundary conditions are applied to obtain two different global buckling modes. The first configuration allows the specimen to freely rotate about the strong axis (x-x) to obtain the flexural–torsional buckling mode (see Fig. 4) whereas the free rotation is for the weak axis (y-y) in the second configuration to get the flexural buckling mode (see Fig. 5). Warping displacements are restrained at two ends for both two configurations. The effective lengths, therefore, can be taken as follows: L_x = L, L_y = L_z = 0.5L for the first configuration; L_y = 0.5 L, L_x = L_z = 0.5L for the second configuration, where L is the specimen length. For bending, the specimen can freely rotate about both the strong axis (x-x) and the weak axis (y-y), and free warping displacements are applied at two ends as illustrated in Fig. 6. The effective lengths in all axes are equal to the specimen length (L). The elastic global buckling loads are determined as presented in Sect. 2 and are given in Table 2.

Table 2

Elastic global buckling loads of the C20015 specimen under compression or bending

h_hole/D	L_hole/D	Compression (kN)				Bending (kNm)
h_hole/D	L_hole/D	F-T	∆%	F	∆%	F-T	∆%
0	0	389.32	100	137.98	100	12.61	100
0.2	0.5	370.2	95.09	136.06	98.61	12.27	97.30
	1	364.04	93.51	134.15	97.22	12.18	96.59
	1.5	357.89	91.93	132.24	95.84	12.09	95.88
	2	351.75	90.35	130.32	94.45	12	95.16
0.5	0.5	329.13	84.54	132.16	95.78	11.49	91.12
	1	314.06	80.67	126.35	91.57	11.23	89.06
	1.5	299.21	76.85	120.53	87.35	10.96	86.92
	2	284.53	73.08	114.71	83.14	10.68	84.69
0.8	0.5	266.49	68.45	126.11	91.40	10.19	80.81
	1	244.78	62.87	114.24	82.79	9.68	76.76
	1.5	224.18	57.58	102.36	74.18	9.15	72.56
	2	204.46	52.52	90.49	65.58	8.59	68.12

F, F-T stand for flexural and flexural–torsional buckling modes; ∆% stands for the deviations between the elastic global buckling loads of the perforated section members and the gross section members

Table 2 shows that the buckling loads of flexural–torsional buckling modes under compression are the most significant impacts due to the appearance of web holes with the 50% capacity reduction compared to those of the gross section specimen, whereas they are about 30% reduction for the other buckling modes.

Both elastic sectional and global buckling loads calculated in this section will be used for the determination of the capacities of the investigated specimen with perforations in Sect. 4.

4 Investigation of Capacities of Cold-Formed Steel Channel Members with Perforations Under Compression or Bending

The obtained elastic buckling loads in Sect. 3 are used to directly determine the capacities of C20015 specimen with its length of 2500 mm and the variation of end boundary conditions by applying the Direct Strength Method design as presented in Sect. 2. There are three component strength values including global buckling strengths (P_ne, M_ne), local buckling strengths (P_nl, M_nl), and distortional buckling strengths (P_nd, M_nd) as listed in Tables 3, 4 and 5, respectively. The member capacities of the investigated specimens are the least of the above strength values as given in Table 6 and illustrated in Fig. 7.

Table 3

Global buckling strengths of the C20015 specimen under compression or bending

Configurations	Hole dimensions		L_hole
Configurations	Hole dimensions		0.5D	D	1.5D	2D
Config. 1 under compression (kN)	No holes		158.200
	h_hole	0.2D	156.712	156.128	155.526	154.905
		0.5D	152.449	150.641	148.706	146.623
		0.8D	143.797	139.935	135.703	131.009
Config. 2 under compression (kN)	No holes		108.037
	h_hole	0.2D	107.139	106.224	105.291	104.339
		0.5D	105.253	102.296	99.148	95.793
		0.8D	102.171	95.509	87.897	79.147
Bending (kNm)	No holes		9.831
	h_hole	0.2D	9.728	9.699	9.670	9.640
		0.5D	9.465	9.367	9.262	9.149
		0.8D	8.935	8.689	8.403	8.063

Table 4

Local buckling strengths of the C20015 specimen under compression or bending

Configurations	Hole dimensions		L_hole
Configurations	Hole dimensions		0.5D	D	1.5D	2D
Config. 1 under compression (kN)	No holes		77.732
	h_hole	0.2D	76.352	76.171	75.985	75.792
		0.5D	75.924	75.351	74.734	74.067
		0.8D	73.155	71.898	70.505	68.941
Config. 2 under compression (kN)	No holes		60.945
	h_hole	0.2D	59.914	59.586	59.250	58.906
		0.5D	59.932	58.846	57.676	56.413
		0.8D	58.801	56.306	53.372	49.875
Bending (kNm)	No holes		8.525
	h_hole	0.2D	6.883	6.870	6.856	6.842
		0.5D	7.611	7.559	7.502	7.441
		0.8D	8.122	7.970	7.791	7.575

Table 5

Distortional buckling strengths of the C20015 specimen under compression or bending

Configurations	Hole dimensions		L_hole
Configurations	Hole dimensions		0.5D	D	1.5D	2D
Config. 1 under compression (kN)	No holes		95.098
	h_hole	0.2D	92.321	88.815	85.003	80.805
		0.5D	92.321	88.815	85.003	80.805
		0.8D	80.304	78.738	76.909	74.723
Config. 2 under compression (kN)	No holes		95.098
	h_hole	0.2D	92.321	88.815	85.003	80.805
		0.5D	92.321	88.815	85.003	80.805
		0.8D	80.304	78.738	76.909	74.723
Bending (kNm)	No holes		8.908
	h_hole	0.2D	8.768	8.533	8.263	7.946
		0.5D	8.768	8.533	8.263	7.946
		0.8D	8.430	8.309	8.162	7.946

Table 6

Member buckling strengths of the C20015 specimen under compression or bending

Configurations	Hole dimensions		L_hole
Configurations	Hole dimensions		0.5D	D	1.5D	2D
Config. 1 under compression (kN)	No holes		77.732
	h_hole	0.2D	76.352	76.171	75.985	75.792
		0.5D	75.924	75.351	74.734	74.067
		0.8D	73.155	71.898	70.505	68.941
Config. 2 under compression (kN)	No holes		60.945
	h_hole	0.2D	59.914	59.586	59.250	58.906
		0.5D	59.932	58.846	57.676	56.413
		0.8D	58.801	56.306	53.372	49.875
Bending (kNm)	No holes		8.525
	h_hole	0.2D	6.883	6.870	6.856	6.842
		0.5D	7.611	7.559	7.502	7.441
		0.8D	8.122	7.970	7.791	7.575

In terms of global buckling strengths (see Table 3), the effects of web holes are insignificant with less than 5% reductions for small hole heights of 0.2D in comparison with those of the gross section members, but they become noticeable with more than 20% reductions for large hole heights of 0.8D.

In terms of distortional buckling strengths (see Table 5), the hole impacts are unchanged for the hole heights of 0.2D and 0.5D, and have minor changes for the hole heights of 0.8D, whereas the effects of hole lengths become noticeable. The reductions of distortional buckling strengths are about 20% for compression and about 10% for bending in comparison with those of gross section members.

In terms of member capacities, it is found that the member failure modes are governed by local buckling modes for both cases due to the small thickness of the investigated specimen (see Tables 3 and 6). For compression, they are seen as downward trends for both two configurations if the hole dimensions increase. The capacity reductions are insignificant for small and intermediate hole heights (h_hole = 0.2D and 0.5D), but they are significant for large hole heights (h_hole = 0.8D), especially in the second configuration. For bending, it is found that the impacts of hole lengths are negligible, as seen in the minor deviations of member capacities with the variation of hole lengths. The novel point herein is the member capacities become higher for larger hole heights as seen in Fig. 7c. As seen in Table 1 for sectional buckling analyses, the local buckling moments of net sections are less than those of the gross section, which means that local buckling modes governed the member failures occurring at the net sections. Therefore, the member capacities are seen as an upward trend with the increase in the hole heights due to the increasing trend of elastic local buckling moments as discussed in Sect. 3.

5 Conclusions

The paper investigated the effects of web hole dimensions on the capacities of cold-formed steel channel members under compression or bending. Variations of boundary conditions were used for the investigation to obtain different global buckling modes. The Direct Strength Method applied for the investigation was regulated in the American specification AISI S100-16. The CUFSM software program was used to support the elastic buckling analyses of the investigated section. The obtained strengths were the base for the analysis of the member behaviors. The several remarks are given as follows:

(1)

For global buckling strengths, the impacts of web holes are negligible for small hole heights, but become significant for large hole heights.

(2)

For distortional buckling strengths, the influence of web holes remains unchanged for hole heights of 0.2D and 0.5D, and has minor changes for hole heights of 0.8D compared to those of the rest of hole heights, whereas the impacts of hole lengths are found to be more significant.

(3)

Member buckling failures are governed by local buckling modes due to the small thickness of the investigated section.

(4)

For member buckling strengths, the compressive capacities undergo decreasing trend if the hole sizes increase, whereas the flexural capacities are found to significantly increase with the increase in the hole heights although they have negligible reductions due to the effects of hole lengths.

(5)

These remarks provide the base understanding of the behavior and strength of cold-formed steel channel members due to the effects of the web holes.

Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

Vorheriges Kapitel Numerical Analysis of Bearing Capacity of Basic Stress Unit Frame of Socket-Type Wheel Buckle Formwork Support Frame Body

Nächstes Kapitel A Method for Determining the Pile Location of Pile Based on the Point Safety Factor Distribution of Reinforced Slope

Yu WW, Laboube RA, Chen H (2020) Cold-formed steel design. Wiley, New York

Hancock GJ, Pham CH (2016) New section shapes using high-strength steels in cold-formed steel structures in Australia. Elsevier Ltd

American Iron and Steel Institute: North American Specification for the Design of Cold-Formed Steel Structural Members (2016)

AS/NZS 4600-2018: Australian/New Zealand Standard—Cold-formed steel structures. The Council of Standards Australia (2018)

Schafer BW, Peköz T (1998) Direct strength prediction of cold-formed members using numerical elastic buckling solutions. In: Fourteenth international specialty conference on cold-formed steel structures

Li Z, Schafer BW (2010) Buckling analysis of cold-formed steel members with general boundary conditions using CUFSM: conventional and constrained finite strip methods. In: Twentieth international specialty conference on cold-formed steel structures. Saint Louis, Missouri, USA

Nguyen VV, Hancock GJ, Pham CH (2015) Development of the thin-wall-2 for buckling analysis of thin-walled sections under generalised loading. In: Proceeding of 8th international conference on advances in steel structures

Pham NH (2022) Investigation of sectional capacities of cold-formed steel SupaCee sections. In: Proceedings of the 8th international conference on civil engineering, vol. 213. ICCE 2021. Springer Singapore, pp 82–94

Pham NH, Vu QA (2021) Effects of stiffeners on the capacities of cold-formed steel channel members. Steel Constr 14(4):270–278CrossRef

10.

Moen CD, Schafer BW (2009) Elastic buckling of cold-formed steel columns and beams with holes. Eng Struct 31(12):2812–2824CrossRef

11.

Moen CD (2008) Direct strength design for cold-formed steel members with perforations. Ph.D. thesis. Johns Hopkins University. Baltimore

12.

Moen CD, Schafer BW (2008) Experiments on cold-formed steel columns with holes. Thin-Walled Struct 46(10):1164–1182CrossRef

13.

Moen CD, Schafer BW (2006) Impact of holes on the elastic buckling of cold- formed steel columns. In: International specialty conference on cold-formed steel structures. pp 269–283

14.

Moen CD, Schafer BW (2010) Extending direct strength design to cold-formed steel beams with holes. In: 20th international specialty conference on cold-formed steel structures—Recent research and developments in cold-formed steel design and construction. pp 171–183

15.

Cai J, Moen CD (2016) Elastic buckling analysis of thin-walled structural members with rectangular holes using generalized beam theory. Thin-Walled Struct 107:274–286CrossRef

16.

Moen CD, Schafer BW (2009) Elastic buckling of thin plates with holes in compression or bending. Thin-Walled Struct 47(12):1597–1607CrossRef

17.

American Iron and Steel Institute (2021) Development of CUFSM hole module and design tables for the cold-formed steel cross-sections with typical web holes in AISI D100. Research report. RP21-01

18.

American Iron and Steel Institute (2021) Development of CUFSM hole module and design tables for the cold-formed steel cross-sections with typical web holes in AISI D100. Research report. RP21-02

19.

Pham NH (2022) Elastic buckling loads of cold-formed steel channel sections with perforations. Civil Eng Res J 13(1):9

Titel: Investigation of Web Hole Effects on Capacities of Cold-Formed Steel Channel Members
verfasst von: Ngoc Hieu Pham
Verlag: Springer Nature Singapore
Buch: Proceedings of the 2nd International Conference on Innovative Solutions in Hydropower Engineering and Civil Engineering
Print ISBN: 978-981-9917-47-1

Electronic ISBN: 978-981-9917-48-8

Copyright-Jahr: 2023
DOI: https://doi.org/10.1007/978-981-99-1748-8_13