Some physical and mechanical properties of date palm trees related to cultural operations industry mechanization

This study was conducted to find some important physical and mechanical properties of date palm trees to be applicable in mechanization of date palm cultural operations industry. To determine the tree trunk mechanical properties as tensile, compressive and shear strength, 9 tree trunk samples were selected at random from different locations within the living trunks and tested by appropriate equipments. Two special tools which had been designed and constructed in Silsoe College were used for tests on the cut trunks and on the leaf bases of living trees. The tree trunks average strengths results showed that the longitudinal tensile strength and longitudinal compressive strength are 60 and 5.34 MPa respectively. It was also indicated that the radial compressive strength is 2.96 MPa and longitudinal shear strength is 1.10 MPa. The experiment was carried out on the tree trunk leaf bases. It showed that the tree leaf base radial compressive strength is 6.38 MPa and the longitudinal leaf base shear strength is 1.00 MPa. The results showed that the safety factor of stresses exerted to the tree by a worker or a light tree climbing machine that climb a healthy producing date tree vary from 7 to 198 which are far from 1, the critical value. The results of tree trunk strengths can be used to reduce the human, tree and machine damages in the date palm cultural operations. These can help to design safe tree shakers and other date palm mechanization machinery by identification of stress limits and safety factors of different stresses exerted to the tree by human or different machines. Results showed that there were significant differences in important physical properties in tree height, spacing, yield and circumference between main cultivation areas around the world. Results can be used for determining acceptable range of sizes and values of features for a new technically acceptable date palm service machine.