E3S Web of Conferences 415, 06017 (2023)
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https://doi.org/10.1051/e3sconf/202341506017

Experimental Study on Structural Behaviour of Steel Wire Meshunder Impact Loading
Masakazu Sugimoto1*, Kanako Koizumi2, Takeshi Arita1, and Toshiyuki Horiguchi 2
1Tokyo Rope International, Shibusawa City Place Eitai, 2-37-28, Eitai, Koto-ku, Tokyo, 135-8306, Japan
2National Defence Academy of Japan, Dept. of Civil Engineering, 1-10-20 Hashirimizu, Yokosuka, 239-8686, Japan

Abstract. In view of application to debris flow/rockfall barrier system, several types of steel wire meshwere selected to verify their basic behaviour under impact load of free fall weight at the controlled testing
environment at an in-house testing facility capable of dropping a heavy weight on approximately 1-metersquare panel made of such steel wire mesh material. Out of the 3 types of wire mesh tested, highperformance chain link endured the highest impact load energy, while newly developed wire mesh showeda high potential of effectively absorbing the impact energy by its plastic deformation along the total lengthof wire components. Both of the above two types of wire mesh are expected to be applied in flexible typedebris flow catchment system in combination with larger opening mesh such as ring net. The newly
developed wire mesh consisting of spirally deformed steel wires behaved as energy-absorbing elements
while transmitting the impact load to the supporting ropes by its own plastic deformation along the total
wire length.

1 Background
Debris flow has long been one of the threatening causesof severe natural disasters in many parts of the world.
Japan is no exception consisting of mountainous regions
amounting to 70% of the whole area, together with
abundant water and numerous typhoon attacks everyyear. There has been a tremendous effort to avoid sucha disaster, and many types of debris flow catchment
structures have been proposed, tested, and installed inmany parts of debris flow prone areas. A recent trend is
the adoption of a flexible system consisting of wire mesh,supporting rope, and anchorage, as opposed to a rigid
steel structure system, fixed on a robust concrete
foundation.
As for the type of wire mesh used in the large-scale
flexible system, the adopted majority has been a socalled ring net composed of several inter-connected
high-tensile steel wire rings. This type of net and its
siblings have proven to perform very well under impact
loading such as rock mass, debris flow substance mainly
consisting of muddy liquid and fallen trees without
detrimental damage. While effectively distributing theload to the support ropes, a large portion of the kinetic
energy of falling substance still seems to be carried overto the supporting ropes, causing large rope tension, andfinally requiring some sort of energy absorption system(brake system) at the rope fixture end or somewhere in
the middle of the rope. The reason for a large portion of
impact energy not being absorbed by the net itself canbe explained by the fact that only a limited small portionof the still wire goes through plastic deformation andthus contributing to the energy absorption.

If the net itself is capable of mobilizing a larger
portion of the wire component throughout the entire
wire length to go through plastic deformation, larger
energy can be absorbed by the net itself and the totalstructural system can be simplified with the decrease in
the support rope strength or elimination of brake system.
The paper presents a chosen several types of wire
mesh material commercially available together withsome newly developed wire mesh materials to verify thebasic nature of their energy absorption capacity, andprovide some valuable information for the futureapplication of these mesh materials.

2 Specimens of steel wire mesh
For a comparison among several wire mesh materials
available for impact force/energy absorption for debris
flow catchment systems, three types of wire meshmaterial were selected as shown in Table 1.
Table 1. Steel Wire Mesh Material.
Type of Wire
MeshWireDiameter

Wire MaterialGradeSpacingA) Normal
Chain Link

4mm 5mm

JIS G 3547
SWMGS-350mm4mm

JIS G 3548
SWGF-450mm

4mm 5mm

JIS G 3547
SWMGS-355mm

B) HighPerformance
Chain Link
C) NewlyDeveloped
Wire Mesh* Corresponding author: sugimoto.masakazu@tokyorope.jp© The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0(https://creativecommons.org/licenses/by/4.0/).

E3S Web of Conferences 415, 06017 (2023)
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https://doi.org/10.1051/e3sconf/202341506017

Table 2. Maximum Energy absorption capacity.

A) Normal Chain Link is the most commonly used
type of wire mesh material for many applications suchas Rock fall barrier and catchment fence in Japan. Its
required minimum tensile strength is 290 MPa.
B) High-performance chain link with high tensile
strength wire (tensile strength of 1230 MPa) is applied
to large energy absorption rock fall catchment fence.
C) Newly developed wire mesh is composed ofspirally fabricated steel wire (made from the same steel
wire grade as A)) and is capable of exerting large
deformation with plastic deformation along the fulllength of wire in comparison to normal straight steelwire.

Type ofWire MeshA) Normal
Chain Link
B) HighPerformance

Chain Link
C) Newly
Developed
Wire Mesh

Wire
Diameter

WeightMax.
DropheightMax.
VerticalDeformation

Approx.
Max.
Energy

4mm

349kg

2m

530 mm

6,800 kJ

4mm

349kg

3m

260 mm

10,300 kJ
over4mm

399kg

1.7 m

310 mm

6,700 kJ

In the above summary, a strictly fair comparison
between wire mesh types cannot be made here, due tothe difference in weight value of the weight (whichcould not be equalized due to the complexity anddifficulty of changing the weight during the executionof several test cases. Also, due to the limitation inmaximum drop height under the in-house testing facility
condition, the maximum energy case for B) could not be
performed in this test. However, it is fair to presume
that A) and C) had nearly equal energy handling
capacity while B) was able to handle more than 50 %larger energy under the test condition.
Normal chain link (4mm wire dia.) was able tocapture around 6,800 kJ of kinetic energy with large
resultant deformation and displacement as shown in Fig.
2 and Fig. 3.

3 Test setup and measured parameters
The impact test was performed at the impact loading test
facility capable of dropping up to approximately 350 kg
spherical weight from around 3.5 meter maximum
height. The 1 meter square specimens supported on 4
sides by both-end-hinge-fixed ropes (Fig.1) were fixed
to a square shape steel frame jig. Parameters such asrope tension, elevation, and acceleration of the weightwas detected throughout the fall/bounce process by useof strain gauges attached to rope end sockets, a razer
beam displacement meter fixed on the steel frame jig, anaccelerometer attached to the free fall steel member (redcoloured object in Fig. 1).

Fig. 2. Successful capture by normal chain link.

Fig. 1. Impact test setup.

4 Test result summary

Fig.3. Large displacement of normal chain link.

In each round of impact testing, the behaviour of thefreefalling weight and the wire mesh was carefully
monitored (Fig.2).
After some 50 rounds of test cases, the approximate
maximum kinetic energy with successful weightcapturing has been deduced for each type of wire mesh.
The results for typical wire mesh cases are summarizedin Table 2.

High-Performance Chain Link was able to capture
up to 10,300 kJ, and was expected to withstand evenhigher energy. But the test setup limitation allowed nofurther testing and the test had to be stopped at this level.
Its basic behaviour under impact loading was similar tothat of normal chain link as shown in Fig. 4.

2E3S Web of Conferences 415, 06017 (2023)
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https://doi.org/10.1051/e3sconf/202341506017

Performance Chain Link is more suitable for impact
load absorption than normal chain link, and can function
as the primary energy absorbing member in a flexible
type debris flow catchment system.
A more detailed analysis of the experiment including thetime history of supporting rope counterforce or weight
movement during the impact loading is underway andwill be reported at the conference.

Fig. 4. Displacement of high-performance chain link after
weight removal.

The newly developed wire mesh captured theweight with less vertical deformation in comparison
with normal chain link (Fig. 5, Table 2). On the otherhand, uniform plastic deformation of the 2 sets of 3
wires close to the mesh center was observed as indicatedin Fig. 6. This indicates the effectiveness of energy
absorption by spirally preformed wire. Since the size of
the weight tip of 300 mm diameter hemispherical head
was too small in relation to the mesh opening size, only
three wires placed close to the mesh center weremobilized for energy absorption. It is expected to havemore numbers of wires to be mobilized if the size of theweight tip is large enough.

5 Future tasks
The series of tests were performed as a first-handapproach to examine the basic behaviour of wire mesh
exposed to impact loading, and to obtain several
properties of the material so that they will provide useful
information to fine-tune and upgrade the wire meshmaterials in hand. It is scheduled to expand the scale ofthe test to replicate the behaviour of these materials
under more realistic setting.
As for the newly developed wire mesh consisting ofspiral wires,
Another area of the future task is to conduct animpact loading test of selected wire mesh materials in
combination with commercially available ring nets ortheir siblings to demonstrate its total performance under
severe impact loading.
In addition, it is also useful to apply numericaldynamic response analysis such as DEM to simulate andverify the behaviour or these mesh system [1, 2], andutilize the analysis method for the design of debris flow
catchment system.

6 Conclusions
The paper presented an impact loading test of several
types of wire mesh material commercially available
together with some newly developed wire meshmaterials to verify their energy absorption capacity.
Further research will be carried out on the advantagesof the newly developed wire mesh with regard to loadtransfer and energy absorption mechanisms.

Fig. 5. Successful capture by newly developed mesh.

References1.

2.
Fig. 6. Uniform plastic deformation of 3 wire lines.

Given the available space in the laboratory setup,the mesh panel size had to be limited to 1 meter square,
and the tip of the falling weight had to be limited to 300
mm diameter hemispherical shape as previously
mentioned with a maximum drop height of 3 meter.
Under this condition, a set of impact loading tests
provided meaningful data implicating that High-3T. Horiguchi, Study of limit state estimation forrock protection net by using 3D-DEM, in Journal of
Structural Engineering, Vol.63A, pp.1061-107(2017)
Y. Sonoda, Impact resistance performance check ofwire ring net guard fence using full scale test andnumerical analysis, in Journal of StructuralEngineering, Vol.57A, pp.811-818 (2011)