DESIGN Chennai. 2 Assistant professor, Srm Institute of

DESIGN AND DEVELOPMENT OF REAR UNDER RIDE PROTECTION DEVICE
(RUPD) WITH IMPROVED ENERGY ABSORPTION

N Manikandan1
and B Prabhakaran2

1 Assistant professor, Srm Institute of science and
Technology, Ramapuram, Chennai.

2 Assistant professor, Srm Institute of science and Technology,
Ramapuram, Chennai.

Email: [email protected],[email protected]

 

Abstract: Every year thousands of
vehicle occupants are killed or injured due to road accidents. Out of which 8%
are due to large truck accidents. Truck under ride accidents represents major
part of the truck related accidents. Rear Under ride Protective Device(RUPD) of
the truck is the main structure for absorbing the energy of collisions during
rear impact. It is essential to improve the energy absorption characteristics
of RUPD due to poor road conditions and primitive passenger safety systems in
India. The current project is aimed at improving the energy absorption capacity
of RUPD, for that two different designs were made and analyzed for improved
deformation and strain energy  storing
capacity. The analysis was carried out in ANSYS and results were evaluated
between two models for improvement in the deformation and strain energy storing
capacity.

Keywords:
RUPD, Impact energy,

1.Introduction

                It is very common incident that during the accident a
passenger vehicle going under the heavy commercial vehicle either from the
rear, front or side. During collision, there is a risk that the passenger
vehicle will penetrate under ( run under) the front or rear part of the truck
and thus there are great chances of fatal injuries to the occupants of the
passenger car. According to the study supported by Natural science foundation
of china and the Natural science foundation of Hunan, it is reported that total
of 92 rear end crashes between trucks on expressways were collected during the
year 2010 to 2016 1. The Under ride protection device is an attachment fixed
to the heavy commercial vehicle which will avoid the under running of the
passenger vehicle at the rear side of a heavy vehicle and further reduces the
chances of severe fatal injuries to the passenger vehicle occupant. Most of the
head injuries and consequent fatalities occur during a rear ride of the
passenger vehicle. The rear under run protection device  prevents the vehicles from being wedged under
the chassis during accidental crashes which significantly increases the safety
of occupants. The significant factor in the rear under production device is it
has resistance to loading forces acting along or parallel to the vehicle
longitudinal axis. This necessitates the requirement of a proper design with
improved energy absorption. Based on the standard IS 14812-2005,
the deformation in the RUPD bar and strain energy can be predicted for failure
before the physical test using Finite element analysis using ANSYS. Based on
the Indian Standard the physical test scenario is developed in the Finite
element modeling to avoid product development for experimental test and to
reduce cost involvement in design development 2.

2.
Finite Element Modeling

     The model created and used for the Finite
element analysis is corrugated steel plate instead the commercially used Solid
RUPD in circular cross section. The Corrugated steel device designed in a
manner to absorb more impact energy and to offer more deformation.

               

      Fig.1: FE modelling of RUPD structure

Fig.2:Cross-Section of
the designed RUPD device

3.Boundary
and Loading Condition

   The chassis member are constrained in all
degrees of freedom. They are very critical member and subjected deformation
under a severe case. The load conditions are applied as per the standard of IS 14812-2005.

Fig.3: Model shows the Boundary and
loading condition

The Load P1=25000 N, P2
=100000 N, and P3 =25000 N are considered as steady load because the analysis
is carried under static structural condition.

4. Material properties of RUPD Bar

    The
RUPD device is assigned with the following material properties for design
validation

Table.1: RUPD bar
material properties

Material

Tensile strength
MPa

Yield strength
MPa

Poison Ratio

Young’s Modulus GPa

Mild Steel

440

370

0.29

205

Copper

220

70

0.36

130

BSK 46

640

500

0.31

210

 

It is clear from the
properties of materials mentioned in Table.1 that BSK 46 has more tensile,
yield and modulus value than the other materials in the list

4.
Result and Discussion

4.1.
Design Validation

    The model shown in
Fig.1 is compared with RUPD with Copper stiffener shown in Fig 4. The result
shows that the change in the design has significant effect on the deformation
characteristics and strain energy. It is clear from the result shown in Table.2
that the design of RUPD with Corrugated structure has more energy carrying
capacity than the RUPD with copper stiffener. The same corrugated steel RUPD is
checked for  different material for any
enhanced performance (i.e. deformation) or energy absorption capability.

Fig.4: RUPD with Copper Stiffener

Table.2: Comparison between RUPD with
Copper Stiffener and RUPD with Corrugated Structure.

Model

Material

Total Deformation
mm

RUPD with
Copper Stiffener

Mild steel

1.262

RUPD with
Corrugated structure

Mild Steel

5.272

 

Fig.5:Deformation plot of RUPD with
Copper Stiffener

Fig.6: Deformation plot of RUPD with
Corrugated structure

4.2.Effect
of material properties on the RUPD bar

      From the table.2, It is
clear that RUPD with corrugated structure has more deformation than the RUPD
with copper stiffener. In the next comparison, the ultimate tensile strength
and yield strength of BSK 46 is higher than mild steel as it is depicted in the
Table.1. It clear explains that there will be improvement in the deformation
and strain energy characteristics of RUPD bar. But the strain energy storing
capacity of RUPD bar for BSK-46 material doesn’t show a significant rise in the
parameter with the Mild steel material as it is depicted in the Table.3.

 

Table.3: Comparison of Mild steel and BSK
46 material property on the RUPD with Corrugated structure.

Model

material

Total deformation
mm

Strain Energy
mJ

RUPD with Corrugated
structure

Mild steel

      5.272

  2410.7

BSK 46

6.4013

2465.3

 

Percentage of variation
between BSK 46 and mild steel in deformation and strain energy is 17% and 2.2%
respectively. It is clear that the change in material property on the designed
model for the same boundary and loading condition does not have any significant
effect on the strain storing capacity but produces a significant effect on the
deformation parameter.

Fig.7: Strain energy plot of RUPD with BSK-46
steel property

Fig.8: Strain energy plot of RUPD with Mild
steel property

 

5.
Conclusion

    In
this study, two different models of RUPD bar were analyzed for same boundary
and loading conditions and two different material properties were assigned for
the model to identify the effect of material property in the design. It is
clear from the analyze the RUPD with corrugated structure has more deformation
and energy carrying capacity than the RUPD with copper stiffeners. Next, the
effect of material property on the designed model have a significant change in
the deformation but not in  strain energy
parameter. It shows a variation of 17% and only 2.2% of variation in
deformation and strain energy respectively between  BSK-46 and mild steel. The change in the
design of RUPD bar has most significant effect on the deformation parameter. It
shows 76% of variation between the two proposed design. So, It is proven that
the corrugated structure can be used as solution for improved energy
absorption. It can be used for the practical heavy vehicles like Heavy
duty trucks, Trailers, Agricultural tractor –trailers, Short haul trucks, Road
trains etc.. When
used in above vehicles, the improved RUPD will play a major role in reducing
the transfer of impact forces to the occupants of smaller vehicles subjected to
rear under ride crash thereby saving many invaluable lives.

 

 

 

 

 

 

 

 DESIGN AND DEVELOPMENT OF REAR UNDER RIDE PROTECTION DEVICE
(RUPD) WITH IMPROVED ENERGY ABSORPTION

N Manikandan1
and B Prabhakaran2

1 Assistant professor, Srm Institute of science and
Technology, Ramapuram, Chennai.

2 Assistant professor, Srm Institute of science and Technology,
Ramapuram, Chennai.

Email: [email protected],[email protected]

 

Abstract: Every year thousands of
vehicle occupants are killed or injured due to road accidents. Out of which 8%
are due to large truck accidents. Truck under ride accidents represents major
part of the truck related accidents. Rear Under ride Protective Device(RUPD) of
the truck is the main structure for absorbing the energy of collisions during
rear impact. It is essential to improve the energy absorption characteristics
of RUPD due to poor road conditions and primitive passenger safety systems in
India. The current project is aimed at improving the energy absorption capacity
of RUPD, for that two different designs were made and analyzed for improved
deformation and strain energy  storing
capacity. The analysis was carried out in ANSYS and results were evaluated
between two models for improvement in the deformation and strain energy storing
capacity.

Keywords:
RUPD, Impact energy,

1.Introduction

                It is very common incident that during the accident a
passenger vehicle going under the heavy commercial vehicle either from the
rear, front or side. During collision, there is a risk that the passenger
vehicle will penetrate under ( run under) the front or rear part of the truck
and thus there are great chances of fatal injuries to the occupants of the
passenger car. According to the study supported by Natural science foundation
of china and the Natural science foundation of Hunan, it is reported that total
of 92 rear end crashes between trucks on expressways were collected during the
year 2010 to 2016 1. The Under ride protection device is an attachment fixed
to the heavy commercial vehicle which will avoid the under running of the
passenger vehicle at the rear side of a heavy vehicle and further reduces the
chances of severe fatal injuries to the passenger vehicle occupant. Most of the
head injuries and consequent fatalities occur during a rear ride of the
passenger vehicle. The rear under run protection device  prevents the vehicles from being wedged under
the chassis during accidental crashes which significantly increases the safety
of occupants. The significant factor in the rear under production device is it
has resistance to loading forces acting along or parallel to the vehicle
longitudinal axis. This necessitates the requirement of a proper design with
improved energy absorption. Based on the standard IS 14812-2005,
the deformation in the RUPD bar and strain energy can be predicted for failure
before the physical test using Finite element analysis using ANSYS. Based on
the Indian Standard the physical test scenario is developed in the Finite
element modeling to avoid product development for experimental test and to
reduce cost involvement in design development 2.

2.
Finite Element Modeling

     The model created and used for the Finite
element analysis is corrugated steel plate instead the commercially used Solid
RUPD in circular cross section. The Corrugated steel device designed in a
manner to absorb more impact energy and to offer more deformation.

               

      Fig.1: FE modelling of RUPD structure

Fig.2:Cross-Section of
the designed RUPD device

3.Boundary
and Loading Condition

   The chassis member are constrained in all
degrees of freedom. They are very critical member and subjected deformation
under a severe case. The load conditions are applied as per the standard of IS 14812-2005.

Fig.3: Model shows the Boundary and
loading condition

The Load P1=25000 N, P2
=100000 N, and P3 =25000 N are considered as steady load because the analysis
is carried under static structural condition.

4. Material properties of RUPD Bar

    The
RUPD device is assigned with the following material properties for design
validation

Table.1: RUPD bar
material properties

Material

Tensile strength
MPa

Yield strength
MPa

Poison Ratio

Young’s Modulus GPa

Mild Steel

440

370

0.29

205

Copper

220

70

0.36

130

BSK 46

640

500

0.31

210

 

It is clear from the
properties of materials mentioned in Table.1 that BSK 46 has more tensile,
yield and modulus value than the other materials in the list

4.
Result and Discussion

4.1.
Design Validation

    The model shown in
Fig.1 is compared with RUPD with Copper stiffener shown in Fig 4. The result
shows that the change in the design has significant effect on the deformation
characteristics and strain energy. It is clear from the result shown in Table.2
that the design of RUPD with Corrugated structure has more energy carrying
capacity than the RUPD with copper stiffener. The same corrugated steel RUPD is
checked for  different material for any
enhanced performance (i.e. deformation) or energy absorption capability.

Fig.4: RUPD with Copper Stiffener

Table.2: Comparison between RUPD with
Copper Stiffener and RUPD with Corrugated Structure.

Model

Material

Total Deformation
mm

RUPD with
Copper Stiffener

Mild steel

1.262

RUPD with
Corrugated structure

Mild Steel

5.272

 

Fig.5:Deformation plot of RUPD with
Copper Stiffener

Fig.6: Deformation plot of RUPD with
Corrugated structure

4.2.Effect
of material properties on the RUPD bar

      From the table.2, It is
clear that RUPD with corrugated structure has more deformation than the RUPD
with copper stiffener. In the next comparison, the ultimate tensile strength
and yield strength of BSK 46 is higher than mild steel as it is depicted in the
Table.1. It clear explains that there will be improvement in the deformation
and strain energy characteristics of RUPD bar. But the strain energy storing
capacity of RUPD bar for BSK-46 material doesn’t show a significant rise in the
parameter with the Mild steel material as it is depicted in the Table.3.

 

Table.3: Comparison of Mild steel and BSK
46 material property on the RUPD with Corrugated structure.

Model

material

Total deformation
mm

Strain Energy
mJ

RUPD with Corrugated
structure

Mild steel

      5.272

  2410.7

BSK 46

6.4013

2465.3

 

Percentage of variation
between BSK 46 and mild steel in deformation and strain energy is 17% and 2.2%
respectively. It is clear that the change in material property on the designed
model for the same boundary and loading condition does not have any significant
effect on the strain storing capacity but produces a significant effect on the
deformation parameter.

Fig.7: Strain energy plot of RUPD with BSK-46
steel property

Fig.8: Strain energy plot of RUPD with Mild
steel property

 

5.
Conclusion

    In
this study, two different models of RUPD bar were analyzed for same boundary
and loading conditions and two different material properties were assigned for
the model to identify the effect of material property in the design. It is
clear from the analyze the RUPD with corrugated structure has more deformation
and energy carrying capacity than the RUPD with copper stiffeners. Next, the
effect of material property on the designed model have a significant change in
the deformation but not in  strain energy
parameter. It shows a variation of 17% and only 2.2% of variation in
deformation and strain energy respectively between  BSK-46 and mild steel. The change in the
design of RUPD bar has most significant effect on the deformation parameter. It
shows 76% of variation between the two proposed design. So, It is proven that
the corrugated structure can be used as solution for improved energy
absorption. It can be used for the practical heavy vehicles like Heavy
duty trucks, Trailers, Agricultural tractor –trailers, Short haul trucks, Road
trains etc.. When
used in above vehicles, the improved RUPD will play a major role in reducing
the transfer of impact forces to the occupants of smaller vehicles subjected to
rear under ride crash thereby saving many invaluable lives.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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