AE	Absorbed Energy
Al	aluminium
Bb/E	Bamboo/Epoxy
B/E	Basalt/Epoxy
C	Carbon
C/E	Carbon/Epoxy
C-G-J	Carbon–Glass–Jute
Cc/P	Coconut coir/Polyester
CFE	Crushing Force Efficiency
CFRP	Carbon-Fibre-Reinforced Composite
CO2	Carbon Dioxide
Ct/E	Cotton/Epoxy
D	Circle inner diameter
D1	Upper circle inner diameter
D2	Lower circle inner diameter
D/t	Diameter-to-thickness ratio
DFL	Design For a Life
FRP	Fibre Reinforced Polymers
F	Flax
F/E	Flax/Epoxy
F-G/P	Flax–Glass/Polyester
G/E	Glass/Epoxy
G/P	Glass/Polyester
GFRP	Glass-Fibre-Reinforced Composite
h	Height cone
H/E	Hemp/Epoxy
HDPE	High-Density Polyethylene
J/E	Jute/Epoxy
J-G	Jute–Glass
J-G-C	Jute–Glass–Carbon
K/E	Kenaf/Epoxy
K-G	Kenaf–Glass
K-G/E	Kenaf–Glass/Epoxy
L	Tube Length
L1	SquareWidth
L1/t	Width-to-thickness ratio
LCA	Life Cycle Assessment
N	Number of layers
NFC	Natural Fibre Composite
OP/E	Oil Palm frond/Epoxy
Pavg	Average Crushing Load
PE	Polyethylene
PLA	Polylactic Acid
Pmax	Maximum Crushing Load
PP	Polypropylene
PU	Polyurethane
PVC	Polyvinyl chloride
r	Square inner radius
R/E	Ramie/Epoxy
S/E	Silk/Epoxy
SEA	Specific Energy Absorption
t	Thickness
VARIM	Vacuum-Assisted Resin Infusion Molding
VARTM	Vacuum-Assisted Resin Transfer Molding
Vf	Fibre Volume Fraction
$\alpha$	Semi-vertex Cone Angle
$\beta$	Trigger Angle