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Comparative analysis of bio-composites vs conventionalcomposites for technical parts
Technical, Economical and Environmental performances
Vitor Hugo Caetano de Carvalho
Instituto Superior Tecnico, Lisboa, Portugal
November 2015
Abstract
The research evaluates the feasibility of natural textile composites as substitute of conventional
materials, on laminated designs. The analysis is asserted from a technical, economic and environ-
mental perspective. The technical performance is studied under a finite element analysis, whereas
the economic and environmental performance of the entire product life is estimated through tool-driver
methods, such as life cycle cost and life cycle assessment, respectively. The models in analysis are a
rocker component and a buggy bonnet, under stress conditions. Essentially, the rocker is a component
of the suspension system of a bicycle and its stiffness is directly associated with the drive manage-
ability. Each technical part is evaluated for two distinct scenarios and five materials. In addition, the
research includes some sensitivity analyses. At last, for a clear knowledge of the possible choices
an integrated methodology, life cycle engineering, is used. The trade-offs are identified and can be
minimized.
Keywords: Natural fiber-reinforced polymer composites, Finite element analysis, Life cycle cost,
Life cycle assessment, Models, Life cycle engineering
1 Introduction
Over the past few decades the market share of
composites has been in continuous growth, thanks
to general economic development and the increased
market penetration. The parts can be designed to
meet the application requirements, providing weight
savings, higher stiffness, higher strength, good vi-
brational damping and low coefficient of thermal
expansion [1]. Therefore, a well-designed part to
be commercially viable must take into account some
key variables such as the material properties, the
part design, cost and end-use or application. The
performance of composites depends on the fiber
(fiber-resin ratio, type, form, orientation), resin and
manufacturing process (MP) [2]. Natural fiber re-
inforced polymer composites (FRC) are emerging
as the replacement to man-made materials, mainly
after the Kyoto agreement. This trend is driven by
changes in the awareness towards green products
by customers; government programs; tax reduction
on renewable; new directives on waste and recy-
cling [3]. Different kinds of natural fibers, due to
their bio renewable nature and inherent eco-friendly
characteristics, offer a number of advantages over
1
other materials.
1.1 Objectives
The main goal of the research is to analyze
the importance of ramie fibers in a design con-
cept by evaluating the technical, economic and en-
vironmental performance. The study concerns the
design and analysis of two case studies, where,
the first is a suspension component of a mountain-
bicycle and the second is a buggy bonnet. The
scope of the work can be divided into specific ob-
jectives, as follows: 1) characterizing mechanical
properties of four laminates (ramie, jute, e-glass
and carbon fiber T300 (CF)); 2) the design stage;
3) finite element analysis (FEA) of a laminated com-
posites, which takes into account the influence of
fiber angle orientation and the stacking sequence;
4) modeling of the product life cycle and related
MP such as hot forging (AHF), wet lay-up (WLU),
blanking and resin transfer molding (RTM). 5) com-
parison of materials from renewable sources; 6)
evaluate the difference of performance between syn-
thetic or man-made and natural FRC; 7) compari-
son between bio-composites (BC) and a conven-
tional material, aluminium alloy (AA).
1.2 Research work approach
The research is developed along the following
points: 1) design of the models, using SolidWorks
2014 (SW) software; 2) before perform a finite ele-
ment method (FEM) analysis, some conditions need
to be defined such as boundary conditions, loading
and mesh element, to illustrate how components
behave in real world; 3) since there are no unidi-
rectional fabrics available commercially for natural
fibers, like ramie and jute, natural and man-made
fabrics present in the research adopt a common
type of weave, a balanced plain weave; 4) identify
and select the interlacing variables. The fiber vol-
ume depends on the MP and the fiber reinforced
form. Also, for comparison purposes the various
kinds of composites can not have the same fiber
volume, due to the variability of the density. If the
fiber volume is constant, the models will have dif-
ferent volumes. To be a fair comparison the com-
posites must have the same dimensions, so the
lamina thickness will be equal in all cases. Which
left another assumption to be made, similar fiber
volume or grammage. The rocker and bonnet com-
posite components are produced from different MP,
and subsequently cannot have the same fiber vol-
ume. From the manufacturing perspective, the rocker
component has at most a typically fiberglass con-
tent up to 25% and the fiber volume of the bonnet
goes up to 40-55%. In this study the maximum fiber
volume content considered for the RTM process is
40%, because it is not a high performance part.
So, based on the market offer, similar fiber vol-
ume and grammage assumptions are applied, re-
spectively, in the rocker and bonnet component. In
other words, for the same lamina thickness, a fiber
with lower density need to have a lower grammage
in order to match similar fiber volume. And if the
grammage is constant, the fiber volume is higher.
5) designing and analyzing of the ply stacking, con-
sidering the influence of the sequence, fiber an-
gle orientation and the deformation; 6) define the
boundaries of the product life cycle; 7) create or
adapt an environment indicator for the ramie fiber.
The SimaPro software libraries, by PRe Consul-
tants, do not contain any environmental indicator
pts/kg for this fiber. Comparison of the available
alternatives based on the production, density and
morphology; 8) input model to depict and analyze
the production processes; 9) LCC and LCA of the
product life cycle; 10) LCE analysis.
2 Composite materials
BC can be classified as either partly ecofriendly,
when one of laminate constituents is non biodegrad-
able or ecofriendly, when both elements result of
2
renewable resources [4].
2.1 Polymeric matrices
In a FRC, the matrix is oblige to: 1) keep the
fibers in place; 2) transfer stresses between the
fibers; 3) provide a barrier against an adverse envi-
ronment, such as moisture and chemicals, and 4)
protect the surface of the fibers from mechanical
degradation [5].
2.2 Natural Fibers
NF, by definition are bio-based fibers from veg-
etable and animal origin. Which includes natural
cellulosic fibers (ramie, jute, etc) and protein based
fibers. Mineral fibers such as asbestos are ex-
cluded, such fibers are not bio-based and contain
products known for health risk [6]. Depending on
the function in the living plant, fibers differ in struc-
tural features and mechanical properties. The fol-
lowing fiber characteristics play an important role
in performance, as referred by [7], the aspect ra-
tio; the cell diameter/cell wall thickness ratio and
the angle oriented cellulose microfibril in the sec-
ondary cell wall layers. However, vegetable fibers
have one crucial concern in terms of end applica-
tion, a large variability of the mechanical properties
from the same specie or even the same plant. Nat-
ural fibers (NF) have some advantages over syn-
thetic fibers such as low density, acceptable mod-
ulus weight ratio, higher acoustic damping, carbon
dioxide sequestration, and biodegradability. NF are
associated with lower costs, depending on the econ-
omy of the countries where such fibers are manu-
factured [4]. Also, NF handling is safer since do
not cause adverse health effects such as allergies,
skin irritation and silicoses, contrary to fiberglass
dusts [8]. Although, there are some disadvantages:
low melting point, high moisture absorption, poor
bonding to polymeric material [9] and relatively low
tensile strength [4] [5]. Enhanced treatments can
be used [9]. BC can be classified as either partly
ecofriendly, when one of laminate constituents is
non biodegradable or ecofriendly, when both ele-
ments result of renewable resources [4].
2.2.1 Ramie
Ramie fibers are obtained from the stem of the
perennial shrub that is also known as Boehmeria
Nivea [10]. The crop can sustain harvesting up to
four times a year. Ramie is propagated through rhi-
zomes for commercial production worldwide. The
stems grow to a height of 2.5 meters. The diameter
of the elementary fiber varies from 4.6 to 126 µm.
Fibers are flat and irregular in shape, with a thick
cell wall and taper to rounded ends. The primary
cell wall is often lignified. It is one of the strongest
natural fibers; when wet, it is even stronger, does
not shrink or lose its shape and dries quickly. Some
experts might not classify ramie as ”natural” for the
reason that, unlike the other bast plants, ramie re-
quires chemical processing to de-gum the fiber. The
solution is far from ideal, it leads to high consump-
tion of chemicals and energy.
2.3 Composite characterization
The theoretically characterization of a compos-
ite is established by a couple of steps. The rule
of mixtures (ROMs) is a method based on a num-
ber of simple and intuitive assumptions, commonly
applied on continuous fibers with elastic behavior.
The properties of the composite are given by math-
ematical expressions, the quantity and arrangement
of its constituents. Fiber-matrix interactions are ex-
plained based on the mechanics of materials ap-
proach. The following requirements must be satis-
fied: a perfect bonding between fibers and matrix,
the distribution of fibers is uniform along the ma-
trix, perfect adhesion, no residual stresses, con-
stituents of the composite behave as linear elastic
up to fracture and the applied load is either parallel
or normal to the fiber direction. Fibers and the resin
have the same longitudinal strain. For approximate
3
values, the fabric layer mechanical properties can
be emulated as two plies separately or together.
When the plies are considered separately, the fab-
ric layer is denoted as being composed by two uni-
directional plies crossed at 90o with each other.
The stiffness layer value is higher than what is ob-
served with a woven fabric, as referred by [11].
Also, the two cross unidirectional plies has lower
tensile strength and higher compressive strength
values. Commonly, the fabric layer is considered
as two plies together. The fabric is replaced by one
single anisotropic layer, x and y being along the
warp and weft direction, respectively. Plain weave
fabric has the same tensile strength value in both
in-plane directions, longitudinal and transversal.
3 Methodology
In a collaboration with the Chemnitz University
of Technology, two models of rocker components
were given, models A and B. Models differ on de-
sign, material and manufacture techniques. In the
manufacturing context, of the dissertation, a pro-
duction volume of 5,000 parts/year [12], is consid-
ered for two technological alternatives, AHF and
WLU. This work also analyzes a bonnet model of a
buggy, which is made by a buggy maker known as
Ancel Reinforced Plastics Lda - Rio Claro, Brazil.
The number of components taken into account is
600 bonnets per year [13], for two methods of fab-
rication, RTM and blanking. Figure 1 shows the
sequence of the analysis.
Figure 1: Stages.
Figures 2 and 3, illustrate the flow chart fol-
lowed in each evaluation.
Figure 2: Technical evaluation.
The scope of the assessment is broken into four
life cycle stages. The production phase takes place
in Lisbon.
Figure 3: Life cycle, cost and environmental impactevaluation.
4 Technical analysis
Several FEA are established to compare data
per FRC. The comparative is obtained by assum-
ing a common setting, same resin properties. Also,
the fabrics are arranged as plain weave, since the
unidirectional form is not available commercially for
natural fibers. In the first instance, the models are
simulated based on the minimum-volume design,
in other words, on a factor of safety basis, similar
or equal to 1. This step helps to narrow down the
number of possible scenarios for the next phase.
While, in the main technical phase, all models must
have a similar deformation as the control material.
If this condition cannot be fulfilled than a lower de-
formation is required. The numerical analysis was
carried out using ABAQUS 6.14 software suite. A
single static load step is defined for the analysis.
Nonlinear effects are not included. In other words,
the material and the geometry are linear. The fail-
ure criteria applied in the composites is Tsai-Hill
criterion. In addition, the model parts in-use needed
to be previously created or reworked on the SW
software. The composite models are composed by
symmetric and balanced laminates. The numerous
fibers in study have different diameters and densi-
ties, so an additional assumption is set up to limit
4
the number of independent variables, equal lamina
thickness as the E-Glass solution. This approach,
allow direct comparison of the solutions, same vol-
ume, the material can be changeable but keep the
same volume (the same number of laminas). Fur-
ther assumptions are case study dependent.
4.1 Theoretical characterization
In the composite industry, thermosetting resins
most often used are the unsaturated polyester and
the vinylester. For high performance use ends the
epoxy and the polyimide [14]. Given the scope
of work, the resin to be used in all candidates is
the unsaturated polyester, Quires 406PA, due to
low cost and fairly good performance. Regarding
the rocker component, the mechanical properties
of the lamina are determined under a similar E-
glass bi-axial fiber volume, based on the market
offer. For the bonnet case study, since RTM pro-
cess has a fiber content up to 40%, it is assumed a
grammage g/m2 similar to E-glass, market-based.
4.2 Case Study: Rocker component
The rocker influences the behavior of the sus-
pension system. The deflecting element consist
in two components, a left and a right component,
pivotally connected to the rear swing arm and the
damper element. This connection ensures trans-
mission of energy while driving, the shock loads on
the rear arm, to the damper element. The element
articulates between two positions: rest suspension
state (35◦) and maximum compression state (65◦)
[15].
4.2.1 Boundary conditions and Loading
Under field tests, the reaction force occurring
was 2250N per component, at a 65◦ angle [16].
As a precaution measure to avoid stress singular-
ities while improving model accuracy and system
safety, a non uniform pressure load is applied, a
cosine pressure distribution. The maximum com-
pression state for both rocker models, A and B,
is simulated by assigning some boundary condi-
tions to the problem. The rocker component has
two holes with pinned constraints and a face roller
support as guidance.
4.2.2 Selecting solid elements
The AA component uses a solid element and
the composite ones a continuum (solid) shell ele-
ment.
4.2.3 Requirements
An aluminum-zinc wrought alloy, 7005, is used
due to be less expensive and stiffener than the
6061. The displacement of model A is used as a
guidance variable on the simulations of model B.
4.2.4 Evaluate
Composite results, based on minimum-volume
design, table 1.
Table 1: Constituent composite comparative
Constituent Thickness [mm] Model [g]
E-glass 11.00 91
CF 6.60 48
Ramie 11.55 81
Jute 13.75 95
Deformation of the ramie composite, figure 4.
Figure 4: Ramie solution, deformation
Results of the main analysis, table 2.
Table 2: Constituent composite comparative
Constituent Thickness [mm] Model [g]
E-glass 19.80 163
CF 12.65 92
Ramie 19.80 136
Jute 24.75 170
5
4.2.5 Sensitivity Analysis
The purpose of this technique is to study the
problem’s response when changing one or two vari-
able values while holding the values of other vari-
ables constant. The weight and the thickness of
the model decreases about of 12.5% and 12.6%,
respectively. In the group analyzed, ramie is the
best natural fiber and the third choice overall, only
lose for the CF and AA.
4.3 Case Study: Bonnet component
The bonnet model was designed as a surface in
the SW software and then imported to the Abaqus
suite.
4.3.1 Boundary conditions and Loading
An uniform load pressure of 800 N is applied
over a circular area of radius 200 mm, simulating a
medium man’s weight, at the center of the bonnet.
The interaction between the bonnet and the vehi-
cle’s main enclosure was assumed as two embed-
ded areas placed symmetrically from the center of
the bonnet, simulating both joints, and a support
base line around the bonnet, figure 5.
Figure 5: Boundary Conditions and Loading.
4.3.2 Selecting shell elements
Since the transverse shear deformation is ne-
glected in thin shell theory, a quadratic shell ele-
ment is used, the triangular shell element STRI65.
4.3.3 Requirements
Bi-axial symmetric composite candidates were
fabricated at room temperature and under constant
pressure by the RTM technique [17]. The original
bonnet model was composed of E-glass continu-
ous filament mat, with 23% of volume fiber, 4mm
thickness, in which the deformation was 23.11mm
[13]. For thesis purposes, a plain weave E-glass
composite is required as the baseline model, in
order to provide direct analysis to the mechanical
properties of the different fibers under the same
assumptions. The composite solution, according
to the Tsai Hill failure criterion (TSAIH), has 4.4
mm of thickness, weights 2.20 kg and the maxi-
mum deformation is about 22.62 mm. The com-
posite mechanical response depends on the lam-
ina’s stacking sequence and orientation angle. As
expected the higher stress occurred in the region at
the border of the two embedded areas. Both val-
ues were identical, due to the not symmetric bon-
net part at y-axis, see bonnet dimensions in annex.
Also, needless to say the deformation decrease
from the composite outside layers to the neutral
line. There are compression stresses (Sxx) and
(Syy) on the upper surface. The final stack lami-
nate sequence is composed with outside layers 45
degree oriented, since the maximum displacement
value is located along the diagonals of the hood.
In other words, the use of laminas (0/90) diminish
the stiffness across the diagonals, which increase
significantly the model’s deformation as the TSAIH
value. The strength of the effect is depend on the
stack sequence, the mid-plane offset distance.
4.3.4 Evaluate
The plain weave E-glass composite maximum
deformation is submitted as design guidance. For
the purpose of these analyses, in order to be as
close as possible of E-glass fabric requirements
and achieve desired results, multiple bonnet candi-
dates are simulated by adding or removing layers,
each layer being 0.55 mm of thickness, arranging
the right layer orientation angle and the specific or-
der in which the plies are stacked. Table 3 illus-
trates some of the results.
6
Table 3: Composite comparative per constituent.
Material Thickness [mm] Weight [kg]
E-glass 4.40 2.20
CF 3.30 1.55
Ramie 4.40 1.94
Jute 4.95 2.12
Remarkably one ply could be saved additionally
in the CF model, which the characteristics would
be 2.75 mm of thickness and 1.30 kg of weight.
The stark performance between composites and
aluminium is a common discussion nowadays. That
said, a bonnet composed of AA is simulated, ac-
cording von Mises criterion, to compare the com-
posite window advantage. The results are 3.13 kg
of weight, with a thickness of 3.40mm. None of the
models match the deformation value of the control
material. If more layers are stacked up, the sec-
ond moment of area increases and subsequently
the deformation decreases even more. The defor-
mation is neglected for comparison purposes since
the solutions have a lower value than the E-glass
composite and the study is done under assump-
tion of elastic material behavior up to fracture. The
worst solution in the weight and thickness contexts
is the AA solution. The CF composite solution sup-
press considerably the competition in the weight
and thickness categories. A similar E-glass defor-
mation is obtained but it has slight lower fiber vol-
ume content. In the natural fiber territory, the jute
is no match for the ramie. From a synthetic versus
natural fibers perspective, CF as first and then the
ramie fiber.
4.3.5 Sensitivity Analysis
As the previous technical part, the bonnet model
is analyzed with the same ramie averaged of [17].
There is clearly a beneficial effect. The mechani-
cal properties of the composite are increased. The
model thickness cut down on one ply, saving weight,
due to a lower second moment of area. The num-
ber of layers has an direct outcome on the model
deformation. Fewer layers, higher deformation.
5 Life cycle
Two individual life cycle approaches, LCC and
LCA. Both multi-step procedures are applied on the
product, based on the system boundaries and the
functional unit. In other words, the process is iter-
ative and depends on the quality and available in-
formation, how far upstream and downstream does
the analysis go. The functional unit stands for the
quantity of the inventory being assigned. Where,
LCIA attempts to establish a linkage between the
product or process and its potential environmen-
tal impacts, classified by potential human health
and environmental impacts of the environmental
resources. LCC stands for the associated costs.
These analyses are attempts to minimize the im-
pacts and expenditures involved [18].
5.1 Determining of key performance indica-tor of ramie fiber
The libraries of SimaPro software do not con-
tain any available indicator for the ramie fiber. Some
fibers are analyzed in some categories to assure
the best approximation to ramie, based on the pro-
duction, chemical and physical properties. Then,
any difference is added in the indicator.
5.2 Methods of fabrication
The cycle time determines the maximum part
production rate and subsequently the number of
parts the capital cost can be spread over. In all
process the building cost is a common denomina-
tor, so it can be neglected. The maintenance cost
is 10% of the machinery initial price. The raw ma-
terial acquisition and the disposal fee are allocated
in the process cost. The fiber is delivered to Valor-
Sul site for incineration, whereas the scrap of the
aluminium is sold.
7
5.3 Use Phase
The cost of assembly is neglected on both cases.
All the concepts are affected in the same way. Rocker
component, does not have any cost or environ-
mental impact associated. Although, in the second
study, the buggy bonnet, the use phase is respon-
sible for most of the environmental impact of a ve-
hicle as result of the fuel consumption.
5.4 End of life (EOL)
EOL refers to the stage when a certain product
reaches the end of its product life cycle. The solid
waste disposal is the same as mentioned earlier.
6 Global evaluation
This section summarizes the results of differ-
ent area analyses. LCE is the art of designing the
product under consideration of the environmental
and economic impacts in conjunction with product
structural analysis. The combination of the data as-
sessed through the different life cycles is a vital key
for the continuous improvement of the product and
to meet customer needs. For a clear knowledge of
the possible choices according to the importance
given to the attributes, the results can be obtained
and viewed through a ternary diagram. Defining
different weight-combinations might change the best
case material for the application.
6.1 Case Study: Rocker component
The various candidates regarding the technical
performance (TP) can be compared according its
stiffness [N/mm] and weight. The rocker compo-
nent stiffness is directly associated with the com-
fort and the stability [12]. Nevertheless, all config-
urations comprehend the same absolute stiffness,
about 1323,53 N/mm. The results of the life cycle
analyses are illustrated in the table 4.
Table 4: Rocker component, LCE.
Material LCC [e] LCA [pt]
E-glass 15.08 0.14007
CF 14.75 0.14624
Ramie 14.37 0.12210
Jute 18.23 0.15193
AA 3.59 0.69196
Figure 6a, illustrates the best material choice,
according the weight of each category. Whereas,
figure 6b, compares the worst of fibers solution with
the AA. The importance given to A and B points,
figure 6a, in the three dimensions: environmental,
economic and technical performance, is (20,30,50)
and (70,20,10), respectively.
(a) CF (blue), Ramie, AA(grey).
(b) Jute (yellow), AA.
Figure 6: Best material choice.
After the ramie solution, the obvious choices
from best to worst are E-glass and jute, as enu-
merated.
6.2 Case Study: Bonnet component
Two attributes of the technical evaluation are
taken into account, such as the mass and the thick-
ness of the models. The deformation is neglected
since the design requirement for comparison pur-
poses of the models is achieved. The deforma-
tion is similar or lower than E-glass baseline model.
Thus, importance-weights need to be assigned for
each attribute. This study assumes a equal distri-
bution of weight for both dimensions in order to be
unbiased. Table 5, summarizes the results of two
life cycle analyses.
8
Table 5: Bonnet component, LCE.
Material LCC [e] LCA [pt]
E-glass 52.28 6.66937
CF 75.96 5.37482
Ramie 44.01 5.80925
Jute 51.19 6.27819
AA 41.97 11.62670
Figure 7a presents the best choices available,
according the importance given to each dimension.
Figure 7b illustrates a comparison between jute and
E-glass candidates.
(a) CF (blue), Ramie(green), AA.
(b) Jute, E-glass (blue).
Figure 7: The best material for a given application,based on the weight of each dimension.
Figures 8a and 8b illustrate the best choice for
two individual scenarios, which the first one is be-
tween jute fiber and AA and the second about the
E-glass fiber and AA.
(a) Jute (yellow), AA. (b) E-glass (blue), AA.
Figure 8: Material choice.
6.3 Fibers Sensitivity Analysis
In a real market context, alternative materials
may not have the same deformation. A sensitive
analysis is done for both case studies, using the
results based on the minimum-volume design.
6.3.1 Case Study: Rocker component
The best material choice is the CF or AA so-
lution, depending on the end-use, figure 9a. The
other fibers solution can be ranked from the best
to the worst, as follows, ramie, E-glass and jute.
In comparison analysis with the AA solution, the
choice depends on the given weights to dimen-
sions. Figure 9b, illustrates the worst fiber solution
in comparison to the AA. Thus, in a identical analy-
sis, the boundaries for E-glass and ramie solutions
appear between the blue and yellow areas.
(a) CF (blue), AA. (b) Jute (yellow), AA.
Figure 9: Best material choice, according to the weightof each category.
6.3.2 Case Study: Bonnet component
All candidates maintain the same properties ex-
cept the CF solution. A ternary diagram is devel-
oped in order to identify possible pattern changes
in comparison with the figure 7a. The CF solution is
reduced in one ply, which results 2.75 mm of nomi-
nal thickness. Figure 10 presents the best solution.
Figure 10: Material selection, regarding the weight ofeach category.
As expected the CF solution is ideal when a
lower and a higher level of importance is given to
the cost and environmental dimensions, respec-
tively. In comparison with the main analysis, fig-
ure 6a, the domain of choice increases. Above the
48.1% of technical importance the CF is the only
solution available.
7 Summary and Conclusions
First phase of rocker component, the ply ori-
entation and the stacking sequence influence the
model deformation, depending on the material and
stacked layers. The first two variables, mention
9
above, with the model geometry play a role in the
variation of the local stress concentration along the
stacked plies. In the minimal-volume assessment,
the ramie fiber cannot compete with the synthetic
fibers, in a thickness context. In a weight context,
the ramie fiber only lose for the CF and AA. CF
solution is the only one that is better than the AA
counterpart, in both contexts. Jute part is clearly
out of its league. Second analysis, the rocker needs
to be as stiff as possible, none of the selected so-
lutions is better than the control material. Bon-
net analysis, the best solution in both scenarios,
is the CF part, followed by the ramie. Stacked
layers has an direct outcome on the part defor-
mation, due to the inertia. A sensitivity analysis
was assessed in both parts, as result there was
weight savings, 13% (rocker) and 14% (bonnet).
This step was done to analyze the effects of the
young modulus and tensile strength. Rocker man-
ufacturing context, approximately 82% of the prod-
uct cost was spent in the workforce, with the excep-
tion of the AA and CF, where is respectively 3.6%
and 58%. The RTM workforce has the following
costs: ramie (11.5%), E-glass and jute (10%) and
CF (6.4%). In the AA is almost non existent. The
major part of the cost is in the use-phase for the
E-glass (47.6%), ramie (49.4%), jute (46.4%) and
AA (83.5%). In the CF case, is in the raw mate-
rial acquisition. Rocker main analysis, the solu-
tion with the lowest cost and the highest environ-
mental impact is the AA. Only when the techni-
cal and economic importance is approximately be-
low 81% and 52%, respectively, the CF or ramie
may be the preferred solution. Ramie fiber is the
best choice, comparing to E-glass and jute. Be-
tween these two, the ideal solution for a high and
low level of technical and economic importance, re-
spectively, is the E-glass. Bonnet study, the best
choice is given between the CF, ramie and AA.
Ramie fiber is the best overall when comparing to
E-glass and jute . Rocker sensitivity analysis, the
best material choices are the CF and the AA. And
then ramie, E-glass and jute, in the fiber context.
LCE method is a decisive consulting tool which al-
lows the business entity to involve a plan of action.
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