Mechanical properties of seven types of wood in laos

Chapter Results and discussion Abstract This study deals with the mechanical and physical properties of seven types of wood in Laos These woods are naturally-grown tree which grow in the middle part of the country Seven types of woods are selected and classified into two groups: hardwoods and softwoods; hardwoods are May Deng, May Tai, May Dou, and May Khen Hine whereas softwoods are May Nhang, May Khen Heua, and May Khe Foy In this project, the focus is on test to determine the various strengths as well as modulus of elasticity and weight density, and specific gravity according to ASTM standard D143 Eight tests were performed in this study such as tension parallel and perpendicular to grain, compression parallel and perpendicular to grain, shear parallel to grain, hardness, static bending and specific gravity Finally, the test results have compared the strength values obtained in this study with some popular woods in US such as Locus(western), Hickory(pecan), Maple(sugar), Oak(swamp white), Larch(western), Douglas fir(coast), and Pine(longleaf) The results found that some wood strengths obtained in the present experiment and some wood strengths in USA are identical and some slight differences Keywords: Seven types of wood; Four hardwoods; Three softwoods; Wood testing; Mechanical and physical properties Chapter Results and discussion Acknowledgements This graduate study program was supported to the funds from ASEAN University Network/Southeast Asia Engineering Education Development Network (AUN/SEED-Net) Japan International Cooperation Agency(JICA) I deeply thank the AUN/SEED-Net for supporting the budget during my study at NUS My sincere appreciation goes to Assoc Prof F S Chau and Assoc Prof S L Toh for all their help and advice in this research project Thanks to the National University of Singapore for giving me chance to study here Also, thanks for providing my research project with funding for expenses on the wood specimens and other resources Finally, I thank Mr Cheong and the laboratory technicians in the experimental mechanics laboratory for their assistance in the experimental work Chapter Results and discussion Table of contents Summary i Acknowledgements iii Table of contents iv List of figures vii List of tables xv Chapter Chapter Chapter Introduction 01 1.1 General 01 1.2 Objectives of the project 02 Literature review 04 2.1 Literature review on work done on wood tests 04 2.2 Literature review on the test methods 08 Laotian wood-characteristics and its applications 11 3.1 Kinds of wood 11 3.2 Features of wood 12 3.3 Wood applications and the purpose of strength tests 13 Chapter Chapter Chapter Results and discussion Experimental work 22 4.1 Method 22 4.2 Selection of materials 22 4.3 Preparation of the specimens 23 4.4 Test methods 24 4.4.1 Tension parallel to grain test 25 4.4.2 Tension perpendicular to grain test 27 4.4.3 Compression parallel to grain test 28 4.4.4 Compression perpendicular to grain test 29 4.4.5 Shear parallel to grain test 30 4.4.6 Hardness test 31 4.4.7 Specific gravity and density 32 4.4.8 Static bending test 34 Results and discussion 51 5.1 The results of physical characteristics and mechanical properties of wood 51 5.1.1 Physical characteristics 51 5.1.2 Mechanical properties 53 5.1.2.1 Strength in tension 53 5.1.2.2 Strength in compression 54 5.1.2.3 Strength in shear 55 5.1.2.4 Hardness 56 Chapter Chapter Results and discussion 5.1.2.5 Strength in static bending 57 5.2 Comparison of wood strengths 58 Conclusion 73 References 75 Appendix A Graphs for static bending test 79 Appendix B Graphs for tension parallel to grain 108 Appendix C Graphs for tension perpendicular to grain test 137 Appendix D Graphs for compression parallel to grain test 152 Appendix E Graphs for compression perpendicular to grain test 167 Appendix F Graphs for shear parallel to grain test 182 Appendix G Graphs for hardness test 197 Appendix H Manner of the failure specimens 212 Appendix I 239 The results of wood properties in eight tests Chapter Results and discussion List of figures Figure 3.1 The hardwood tree 19 Figure 3.2 The softwood tree 19 Figure 3.3 Schematic diagram of softwood, illustrating the relative appearance of tracheids 20 Figure 3.4 Schematic diagram of hardwood, illustrating the relative appearance of vessels and tracheids (vascular cells) 20 Figure 3.5 Cross section of tree trunk: A = outer bark (dry dead tissue), B = inner bark (living tissue), C = cambium, D = sapwood, E = heartwood, F = pith, G = wood rays 21 Figure 3.6 Diagrammatic illustration of the principal structural features 21 Figure 4.1 Methods of sawing logs for lumber or beam: flat-sawn and quarter-sawn 39 Figure 4.2 Method of flat (or plain) sawing wood in Laos 40 Figure 4.3 The samples of the flat-cut woods in different dimensions 40 Figure 4.4 Rectangular pieces for making wood specimens 41 Figure 4.5 Wood specimen and its dimension, and direction of applied force for tension parallel to grain test (dimension in mm) 41 Wood specimen and its dimension, and direction of applied force for tension perpendicular to grain test ( dimension in mm ) 42 Wood specimen and its dimension and direction of applied force for compression parallel to grain test (dimension in mm) 42 Wood specimen and its dimension and direction of applied force for compression perpendicular to grain test (dimension in mm) 43 Figure 4.6 Figure 4.7 Figure 4.8 Figure 4.9 Wood specimen and its dimension and direction of applied force for static bending test (dimension in mm) 43 Figure 4.10 Wood specimen and its dimension and direction of applied force for shear parallel to grain test (dimension in mm) 44 Chapter Results and discussion Figure 4.11 Tension parallel to grain test (May Khen Heua e1) 44 Figure 4.12 Graph for calculating the modulus of elasticity in axial tension (May Khe Foy g6) 45 Figure 4.13 Tension perpendicular to grain (May Nhang d6) 45 Figure 4.14 Compression parallel to grain test (May Khen Heua e1) 46 Figure 4.15 Compression perpendicular to rain test (May Dou c1) 47 Figure 4.16 Shear parallel to grain test (May Khe Foy g5) 47 Figure 4.17 Hardness test (May Khe Heua e2) 48 Figure 4.18 The performance of wood specimens in a conventional oven 49 Figure 4.19 Static bending test (May Khen Heua e1) 50 Figure 4.20 Load vs deflection under the proportional limit in static bending (May Deng) 50 Figure 5.1 Static bending strengths of woods in comparison with some US woods 69 Figure 5.2 Compressive strength of woods in comparison with some US woods 70 Figure 5.3 Shearing strengths of woods in comparison with some US woods 71 Figure 5.4 Hardness of woods in comparison with some US woods 72 Figure A.1.1.a1-a6 Load vs displacement in static bending for May Deng 81 Figure A.1.2.b1-b6 Load vs displacement in static bending for May Tai 83 Figure A.1.3.c1-c6 Load vs displacement in static bending for May Dou 85 Figure A.1.4.d1-d6 Load vs displacement in static bending for May Nhang 87 Figure A.1.5.e1-e6 Load vs displacement in static bending for May Khen Heua 89 Figure A.1.6.f1-f6 Load vs displacement in static bending for May Khen Hine 91 Figure A.1.7.g1-g6 Load vs displacement in static bending for May Khe Foy 93 Chapter Results and discussion Figure A.2.a1-a6 Load vs displacement in static bending for May Deng 95 Figure A.2.b1-b6 Load vs displacement in static bending for May Tai 97 Figure A.2.3.c1-c6 Load vs displacement in static bending for May Dou 99 Figure A.2.4.d1-d6 Load vs displacement in static bending for May Nhang 101 Figure A.2.5.e1-e6 Load vs displacement in static bending for May Khen Heua 103 Figure A.2.6.f1-f6 Load vs displacement in static bending for May Khen Hine 105 Figure A.2.7.g1-g6 Load vs displacement in static bending for May Khe Foy 107 Figure B.1.1a1-a6 Load vs displacement in tension parallel to grain test (May Deng) 110 Figure B.1.2b1-b6 Load vs displacement in tension parallel to grain test (May Tai) 112 Figure B.1.3c1-c6 Load vs displacement in tension parallel to grain test (May Dou) 114 Figure B.1.4d1-d6 Load vs displacement in tension parallel to grain test (May Nhang) 116 Figure B.1.5e1-e6 Load vs displacement in tension parallel to grain test (May Khen heua) 118 Figure B.1.6f1-f6 Load vs displacement in tension parallel to grain test ( May Khen Hine ) 120 Figure B.1.7g1-g6 Load vs displacement in tension parallel to grain test (May Khe Foy) 122 Figure B.2.1a1-a6 Load vs displacement in tension parallel to grain test (May Deng) 124 Load vs displacement in tension parallel to grain test (May Tai) 126 Load vs displacement in tension parallel to grain test (May Dou) 128 Load vs displacement in tension parallel to grain test (May Nhang) 130 Figure B.2.2b1-b6 Figure B.2.3c1-c6 Figure B.2.4d1-d6 Chapter Results and discussion Figure B.2.5e1-e6 Load vs displacement in tension parallel to grain test (May Khen Heua) 132 Figure B.2.6f1-f6 Load vs displacement in tension parallel to grain test (May Khen Hine) 134 Figure B.2.7g1-g6 Load vs displacement in tension parallel to grain test (May Khe Foy) 136 Figure C.1.a1-a6 Load vs displacement in tension perpendicular to grain (May Deng) 139 Load vs displacement in tension perpendicular to grain (May Tai) 141 Load vs displacement in tension perpendicular to grain (May Dou) 143 Load vs displacement in tension perpendicular to grain ( May Nhang) 145 Load vs displacement in tension perpendicular to grain (May Khen Heua) 147 Load vs displacement in tension perpendicular to grain (May Khen Hine) 149 Load vs displacement in tension perpendicular to grain (May Khe Foy) 151 Load vs displacement in compression parallel to grain (May Deng) 154 Load vs displacement in compression parallel to grain (May Tai) 156 Load vs displacement in compression parallel to grain (May Dou) 158 Load vs displacement in compression parallel to grain (May Nhang) 160 Load vs displacement in compression parallel to grain (May Khen Heua) 162 Load vs displacement in compression parallel to grain (May Khen Hine) 164 Figure C.2.b1-b6 Figure C.3.c1-c6 Figure C.4.d1-d6 Figure C.5.e1-e6 Figure C.6.f1-f6 Figure C.7.g1-g6 Figure D.1.a1-a6 Figure D.2.b1-b6 Figure D.3.c1-c6 Figure D.4.d1-d6 Figure D.5.e1-e6 Figure D.6.f1-f6 Chapter Results and discussion Figure D.7.g1-g6 Figure E.1.a1-a6 Load vs displacement in compression parallel to grain (May Khe Foy) 166 Load vs displacement in compression perpendicular to grain test (May Deng) 169 Figure E.2.b1-b6 Load vs displacement in compression perpendicular to grain test (May Tai) 171 Figure E.3.c1-c6 Load vs displacement in compression perpendicular to grain test (May Dou) 173 Figure E.4.d1-d6 Load vs displacement in compression perpendicular to grain test (May Nhang) 175 Figure E.5.e1-e6 Load vs displacement in compression perpendicular to grain test (May Khen Heua) 177 Figure E.6.f1-f6 Load vs displacement in compression perpendicular to grain test (May Khen Hine) 179 Figure E.7.g1-g6 Load vs displacement in compression perpendicular to grain test (May Khe Foy) 181 Figure F.1.a1-a6 Load vs displacement in shear parallel to grain test (May Deng) 184 Figure F.2.b1-b6 Load vs displacement in shear parallel to grain test (May Tai) 186 Figure F.3.c1-c6 Load vs displacement in shear parallel to grain test (May Dou) 188 Figure F.4.d1-d6 Load vs displacement in shear parallel to grain test (May Nhang) 190 Figure F.5.e1-e6 Load vs displacement in shear parallel to grain test (May Khen Heua) 192 Figure F.6.f1-f6 Load vs displacement in shear parallel to grain test (May Khen Hine) 194 Load vs displacement in shear parallel to grain test (May Khe Foy) 196 Figure G.1.a1-a6 Load vs displacement in hardness test (May Deng) 199 Figure G.2.b1-b6 Load vs displacement in hardness test (May Tai) 201 Figure F.7.g1-g6 10 Abstract Table I.6.3 The results of the hardness test (May Dou) No Dimensions mm B H L Weight g Load kgf Load kgf Average Load kgf Disp mm Disp mm c1 48.2 47.8 150 309.5 830.75 870.75 850.75 5.003 5.01 c2 47.6 47.8 150 297.0 681.00 716.50 698.75 5.003 5.03 c3 49.4 48.4 150 318.5 795.00 777.25 786.125 5.004 5.02 c4 48.4 48.0 150 328.5 1001.87 915.00 958.437 5.004 5.03 c5 48.8 47.0 150 306.0 731.75 781.75 756.75 5.003 5.02 c6 47.5 48.8 150 306.5 1059.37 976.25 1017.813 5.002 5.02 Average value 844.77 Standard deviation 122.81 Table I.6.4 The results of the hardness test (May Nhang) No Dimensions mm B H L Weight g Load kgf Load kgf Average Load kgf Disp mm Disp mm d1 48.4 47.8 150 261.0 395.25 426.00 410.625 5.004 5.03 d2 47.8 47.3 150 271.5 477.00 477.75 477.375 5.004 5.01 d3 45.2 49.0 150 242.0 388.75 429.00 408.875 5.004 5.01 d4 48.3 47.6 150 308.5 632.75 456.25 544.50 5.004 5.01 d5 51.0 45.8 150 242.5 372.50 374.50 373.50 5.003 5.01 d6 47.8 47.7 150 264.5 431.25 447.00 439.125 5.004 5.01 Average value 442.33 Standard deviation 60.89 280 Abstract Table I.6.5 The results of the hardness test (May Khen Heua) No Dimensions mm B H L Weight g Load kgf Load kgf Average Load kgf Disp mm Disp mm e1 46.0 47.6 150 234.5 389.25 361.75 375.5 5.004 5.01 e2 45.1 47.7 150 237.0 457.50 463.00 460.25 5.003 5.01 e3 46.1 47.6 150 251.5 481.75 484.75 483.25 5.003 5.02 e4 48.1 47.0 150 249.0 442.00 463.00 452.50 5.003 5.02 e5 46.7 47.5 150 271.0 482.50 491.25 486.875 5.002 5.02 e6 48.3 45.6 150 246.0 377.00 399.25 388.125 5.004 5.02 Average value 441.08 Standard deviation 47.91 Table I.6.6 The results of the hardness test (May Khen Hine) No Dimensions mm B H L Weight g Load kgf Load kgf Average Load kgf Disp mm Disp mm f1 48.0 47.8 150 319.5 736.50 793.75 764.875 5.004 5.01 f2 47.3 47.5 150 293.5 751.00 749.00 750.00 5.004 5.02 f3 48.1 47.5 150 322.5 738.25 759.50 748.875 5.004 5.02 f4 48.5 48.2 150 304.0 664.00 659.75 661.875 5.003 5.02 f5 48.0 47.5 150 342.0 814.75 780.75 797.75 5.004 5.01 f6 48.6 47.5 150 314.5 741.25 740.75 741.00 5.004 5.00 Average value 744.06 Standard deviation 45.03 281 Abstract Table I.6.7 The results of the hardness test (May Khe Foy) No Dimensions mm B H L Weight g Load kgf Load kgf Average Load kgf Disp mm Disp mm g1 49.0 48.6 150 322.5 733.00 743.00 738.00 5.004 5.02 g2 48.2 48.6 150 312.5 672.50 658.25 665.375 5.004 5.02 g3 48.6 46.3 150 323.0 746.00 767.50 756.75 5.003 5.02 g4 49.1 48.2 150 311.5 682.75 710.25 696.50 5.003 5.02 g5 49.0 46.7 150 307.5 633.00 591.50 612.25 5.003 5.02 g6 49.5 46.7 150 290.5 646.00 683.25 664.625 5.00 5.02 Average value 688.92 Standard deviation 53.09 Table I.6.8 The final results of the hardness test (Seven types of wood) Type of wood Max Load kgf Standard deviation a May Deng 927.86 93.86 b May Tai 645.98 80.63 c May Dou 844.77 122.81 d May Nhang 442.33 60.89 e May Khen Heua 441.08 47.91 f May Khen Hine 744.06 45.03 g May Khe Foy 688.92 53.09 282 Abstract Appendix I.7 The test results of the specific gravity and the weight density Table I.7.1 The results of the specific gravity (May Deng) No Initial dimensions cm B H L I weight g F weight g Moisture Content % Volume Cm3 Specific gravity a1 4.83 4.87 14.83 371.5 322.5 10.85 348.833 0.925 a2 4.73 4.73 15.09 322.0 288.5 11.61 337.607 0.855 a3 4.93 4.79 15.09 372.5 336.0 10.86 356.558 0.942 a4 4.80 4.90 15.13 349.5 312.5 11.84 355.857 0.878 a5 4.80 4.93 15.03 368.5 329.0 12.01 355.521 0.925 a6 4.71 4.94 15.08 341.0 299.5 13.86 Average value 11.84 Standard deviation 1.10 328.524 0.912 0.906 0.033 Table I.7.2 The results of the weight density (May Deng) No Final dimensions cm B H L I weight g F weight g Moisture Content % Volume Cm3 Weight density g/c.c a1 4.74 4.73 14.80 322.5 322.5 0.00 331.684 0.972 a2 4.65 4.55 15.09 288.5 288.5 0.00 319.266 0.904 a3 4.88 4.71 15.07 336.0 336.0 0.00 346.380 0.970 a4 4.72 4.73 15.12 312.5 312.5 0.00 337.563 0.926 a5 4.75 4.79 14.99 329.0 329.0 0.00 341.06 0.965 a6 4.57 4.78 15.04 299.5 306.975 0.976 0.952 0.030 299.5 0.00 Average value 0.00 Standard deviation 0.00 283 Abstract Table I.7.3 The results of the specific gravity (May Tai) No Initial dimensions cm B H L I weight g F weight g Moisture Content % Volume Cm3 Specific gravity b1 4.88 4.86 15.15 315.5 282.0 11.88 359.309 0.785 b2 4.85 4.71 15.25 300.0 265.0 13.21 348.363 0.761 b3 4.87 4.73 15.30 271.0 237.5 14.11 352.437 0.674 b4 4.88 4.84 15.28 277.5 245.0 13.27 360.901 0.679 b5 4.79 4.95 15.21 287.5 254.5 12.97 360.636 0.706 b6 4.83 4.84 14.99 278.5 244.0 14.14 Average value 13.26 Standard deviation 0.83 350.424 0.696 0.717 0.046 Table I.7.4 The results of the weight density (May Tai) No Final dimensions cm B H L I weight g F weight g Moisture Content % Volume Cm3 Weight density g/c.c b1 4.81 4.79 15.12 282.0 322.5 0.00 348.360 0.809 b2 4.78 4.66 15.24 265.0 288.5 0.00 339.470 0.781 b3 4.81 4.66 15.23 237.5 336.0 0.00 341.370 0.696 b4 4.78 4.76 15.22 245.0 312.5 0.00 346.300 0.707 b5 4.74 4.79 15.17 254.5 329.0 0.00 344.430 0.739 b6 4.73 4.75 14.94 244.0 299.5 0.00 Average value 0.00 Standard deviation 0.00 335.660 0.727 0.743 0.044 284 Abstract Table I.7.5 The results of the specific gravity (May Dou) No Initial dimensions cm B H L I weight g F weight g Moisture Content % Volume Cm3 Specific gravity c1 4.87 4.80 15.11 328.0 302.0 8.61 353.211 0.855 c2 4.84 4.80 14.95 299.0 271.0 10.33 347.318 0.780 c3 4.90 4.87 15.01 300.5 269.5 14.50 358.183 0.752 c4 4.83 4.85 15.03 320.0 291.0 9.97 352.085 0.827 c5 4.58 4.86 15.07 293.0 262.5 11.62 335.440 0.783 c6 4.88 4.78 15.08 319.0 292.5 9.06 Average value 10.18 Standard deviation 1.23 351.762 0.832 0.805 0.039 Table I.7.6 The results of the weight density (May Dou) No Final dimensions cm B H L I weight g F weight g Moisture Content % Volume Cm3 Weight density g/c.c c1 4.81 4.76 15.09 302.0 302.0 0.00 345.494 0.874 c2 4.80 4.74 14.93 271.0 271.0 0.00 339.687 0.798 c3 4.81 4.76 15.00 269.5 269.5 0.00 343.434 0.785 c4 4.75 4.76 15.03 291.0 291.0 0.00 339.828 0.856 c5 4.48 4.78 15.01 262.5 262.5 0.00 321.430 0.817 c6 4.83 4.76 15.04 292.5 292.5 0.00 Average value 0.00 Standard deviation 0.00 345.781 0.846 0.829 0.035 285 Abstract Table I.7.7 The results of the specific gravity (May Nhang) No Initial dimensions cm B H L I weight g F weight g Moisture Content % Volume Cm3 Specific gravity d1 4.82 4.84 14.96 269.0 233.0 15.45 348.998 0.668 d2 4.81 4.86 14.96 267.0 232.0 15.09 349.713 0.663 d3 4.55 4.99 14.94 264.0 231.0 14.29 339.205 0.681 d4 5.15 4.40 14.95 301.0 262.0 14.89 337.843 0.776 d5 4.81 4.85 14.97 256.0 226.0 13.27 349.227 0.647 d6 4.84 4.71 15.04 255.0 222.0 14.86 Average value 14.64 Standard deviation 0.77 342.857 0.647 0.680 0.048 Table I.7.8 The results of the weight density (May Nhang) No Final dimensions cm B H L I weight g F weight g Moisture Content % Volume Cm3 Weight density g/c.c d1 4.57 4.73 14.95 231.0 231.0 0.00 323.160 0.715 d2 4.55 4.76 14.93 230.0 230.0 0.00 323.354 0.711 d3 4.38 4.85 14.91 229.0 229.0 0.00 316.733 0.723 d4 4.87 4.21 14.92 260.0 260.0 0.00 305.900 0.850 d5 4.70 4.68 14.94 224.0 224.0 0.00 328.620 0.682 d6 4.70 4.61 15.01 220.0 220.0 0.00 Average value 0.00 Standard deviation 0.00 325.222 0.676 0.726 0.063 286 Abstract Table I.7.9 The results of the specific gravity (May Khen Heua) No Initial dimensions cm B H L I weight g F weight g Moisture Content % Volume Cm3 Specific gravity e1 4.79 4.66 14.93 233.0 209.5 11.22 333.258 0.629 e2 4.67 4.95 15.01 247.0 220.0 12.27 346.978 0.634 e3 4.65 4.80 14.85 246.0 220.0 11.82 331.452 0.664 e4 4.80 4.47 14.89 240.0 216.5 10.85 319.479 0.678 e5 4.76 4.61 14.92 252.0 225.5 11.75 327.398 0.689 e6 4.66 4.78 15.09 236.5 212.0 11.56 Average value 11.58 Standard deviation 0.49 336.126 0.631 0.654 0.026 Table I.7.10 The results of the weight density (May Khen Heua) No Final dimensions cm B H L I weight g F weight g Moisture Content % Volume Cm3 Weight density g/c.c e1 4.76 4.60 14.91 209.5 209.5 0.00 326.469 0.642 e2 4.63 4.87 14.98 220.0 220.0 0.00 337.770 0.651 e3 4.62 4.77 14.84 220.0 220.0 0.00 327.035 0.673 e4 4.79 4.45 14.87 216.5 216.5 0.00 316.961 0.683 e5 4.76 4.61 14.88 225.5 225.5 0.00 326.521 0.691 e6 4.62 4.74 15.06 212.0 212.0 0.00 Average value 0.00 Standard deviation 0.00 329.796 0.643 0.664 0.021 287 Abstract Table I.7.11 The results of the specific gravity (May Khen Hine) No Initial dimensions cm B H L I weight g F weight g Moisture Content % Volume Cm3 Specific gravity f1 4.80 4.84 15.06 330.0 297.5 10.92 349.874 0.850 f2 4.83 4.80 15.22 312.5 276.5 13.02 352.860 0.784 f3 4.70 4.82 15.07 327.5 291.0 12.54 341.396 0.852 f4 4.86 4.86 14.97 311.5 281.0 10.85 353.585 0.795 f5 4.82 4.85 14.98 309.5 280.0 10.54 350.187 0.800 f6 4.81 4.88 15.10 321.0 288.5 11.27 Average value 11.52 Standard deviation 1.01 354.807 0.813 0.816 0.029 Table I.7.12 The results of the weight density (May Khen Hine) No Final dimensions cm B H L I weight g F weight g Moisture Content % Volume Cm3 Weight density g/c.c f1 4.76 4.77 15.03 297.5 297.5 0.00 341.259 0.872 f2 4.77 4.77 15.19 276.5 276.5 0.00 345.616 0.800 f3 4.54 4.79 15.06 291.0 291.0 0.00 327.503 0.889 f4 4.78 4.78 14.97 281.0 281.0 0.00 342.040 0.822 f5 4.79 4.79 14.96 280.0 280.0 0.00 343.244 0.816 f6 4.75 4.79 15.09 288.5 288.5 0.00 Average value 0.00 Standard deviation 0.00 343.335 0.840 0.840 0.034 288 Abstract Table I.7.13 The results of the specific gravity (May Khe Foy) No Initial dimensions cm B H L I weight g F weight g Moisture Content % Volume Cm3 Specific gravity g1 4.84 4.79 15.15 308.0 267.0 15.36 351.231 0.760 g2 4.95 4.92 15.22 326.0 284.0 14.79 370.668 0.766 g3 4.77 4.92 15.24 342.0 299.0 14.38 357.658 0.836 g4 4.82 4.79 15.04 344.0 301.0 14.29 347.240 0.867 g5 4.72 4.92 15.11 327.0 286.0 14.34 350.890 0.815 g6 4.95 4.72 15.05 291.0 253.0 15.02 Average value 14.69 Standard deviation 0.43 351.628 0.720 0.794 0.055 Table I.7.14 The results of the weight density (May Khe Foy) No Final dimensions cm B H L I weight g F weight g Moisture Content % Volume Cm3 Weight density g/c.c g1 4.63 4.55 15.12 267.0 267.0 0.00 318.525 0.838 g2 4.75 4.67 15.18 284.0 284.0 0.00 336.730 0.843 g3 4.51 4.71 15.21 299.0 299.0 0.00 323.092 0.925 g4 4.58 4.64 15.00 301.0 301.0 0.00 318.768 0.944 g5 4.50 4.71 15.10 286.0 286.0 0.00 320.044 0.894 g6 4.72 4.52 15.03 253.0 253.0 0.00 Average value 0.00 Standard deviation 0.00 320.656 0.789 0.830 0.131 289 Abstract Table I.7.15 The final values of the weight density and specific gravity (Seven types of wood) No Wood Specific gravity STDV Moisture content % STDV STDV 1.10 Weight density g/c.c 0.952 a May Deng 0.906 0.033 11.84 b May Tai 0.717 0.046 13.26 0.83 0.743 0.044 c May Dou 0.805 0.039 10.18 1.23 0.829 0.035 d May Nhang 0.680 0.048 14.64 0.77 0.726 0.063 e May Ken Heua 0.654 0.026 11.58 0.49 0.664 0.021 f May Khen Hine 0.816 0029 11.52 1.01 0.840 0.034 g May Khe Foy 0.794 0.055 14.69 0.43 0.830 0.131 290 0.030 Abstract Appendix I The test results of static bending test Table I.8.1 The results of static bending test (Mau Deng) No B mm H mm Sx mm3 Load kgf Deflection mm Bending Strength MPa Modulus Of elasticity GPa Stiffness N.m2 a1 48.0 48.5 18818.0 1220.00 14.426 113.46 14.67 6695.79 a2 47.0 48.5 18425.9 1330.00 22.648 126.32 13.96 6236.60 a3 48.0 50.0 20000.0 1173.75 15.973 102.70 13.18 6589.10 a4 48.5 49.0 19408.1 1460.62 19.402 131.70 15.30 7277.32 a5 48.0 49.5 19602.0 1440.62 17.455 128.61 14.8 7175.85 a6 45.0 48.0 17280.0 940.00 11.90 13.97 1.25 4934.84 6484.92 851.47 Table I.8.2 14.347 95.20 Average value 116.33 Standard deviation 15.02 The results of static bending test (May Tai) No B mm H mm Sx mm3 Load kgf Deflection mm Bending Strength MPa Modulus Of elasticity GPa Stiffness N.m2 b1 48.5 50.0 20208.3 1381.25 25.019 119.61 14.76 7458.11 b2 47.5 48.5 18621.9 676.875 9.7935 63.61 11.07 4999.94 b3 48.0 50.0 20000.0 875.625 16.750 76.62 9.12 4558.33 b4 48.5 49.5 19806.2 928.75 17.284 82.06 8.70 4265.06 b5 48.0 48.0 18432.0 963.75 19.8975 91.50 10.11 4472.15 b6 48.5 48.5 19014.0 918.75 18.5775 84.56 Average value 86.33 Standard deviation 18.80 8.62 10.40 2.34 3973.15 4954.46 1272.64 291 Abstract Table I.8.3 The results of static bending test (May Dou) No B mm H mm Sx mm3 Load kgf Deflection mm Bending Strength MPa Modulus Of elasticity GPa Stiffness N.m2 c1 48.0 48.5 18818.0 1090.62 11.7315 101.42 14.99 6844.28 c2 48.5 49.0 19408.1 1371.87 15.088 123.70 17.36 8254.87 c3 48.5 48.7 19171.1 995.625 14.488 90.88 12.16 5676.86 c4 48.0 48.0 18432.0 1311.87 15.228 124.55 15.01 6641.55 c5 47.0 48.5 18425.9 766.25 13.535 72.77 10.77 4812.36 c6 48.0 48.5 18818.0 1203.12 11.8845 111.89 Average value 104.20 Standard deviation 20.13 17.25 14.59 2.67 7871.14 6683.51 1297.83 Table I.8.4 The results of static bending test (May Nhang) No B mm H mm Sx mm3 Load kgf Deflection mm Bending Strength MPa Modulus Of elasticity GPa Stiffness N.m2 d1 47.0 48.0 18048.0 753.75 18.9595 73.09 8.54 3700.40 d2 47.0 48.0 18048.0 665.75 16.481 64.55 7.56 3360.97 d3 49.0 45.0 1537.5 529.25 14.185 56.01 8.08 3005.97 d4 45.0 51.5 19449.8 1152.5 16.192 103.70 14.57 7300.18 d5 48.0 48.5 18818.0 810.75 16.881 75.40 9.72 4434.35 d6 48.0 48.5 18818.0 950.625 17.5735 88.40 Average value 76.86 Standard deviation 17.07 11.15 9.97 2.58 5088.98 4481.81 1572.20 292 Abstract Table I.8.5 The results of static bending test (May Khen Heua) No B mm H mm Sx mm3 Load kgf Deflection mm Bending Strength MPa Modulus Of elasticity GPa Stiffness N.m2 e1 47.0 48.0 18048.0 815.5 21.4735 79.07 8.54 3687.32 e2 48.5 46.5 17478.2 918.5 26.664 91.96 9.14 3714.48 e3 45.5 48.0 17472.0 895.25 30.3345 89.67 8.05 3376.84 e4 48.5 45.5 16734.5 852.0 26.356 89.10 9.25 3523.82 e5 48.0 46.5 17298.0 847.5 29.1235 85.74 8.17 3286.44 e6 48.0 49.0 19208.0 956.25 15.45 9.77 2.83 7272.31 4143.54 1541.94 Table I.8.6 20.580 87.12 Average value 87.11 Standard deviation 4.48 The results of static bending test (May Khen Hine) No B mm H mm Sx mm3 Load kgf Deflection mm Bending Strength MPa Modulus Of elasticity GPa Stiffness N.m2 f1 48.0 48.5 18818.0 1455.62 24.8025 135.37 13.16 6007.22 f2 48.0 48.0 18432.0 1333.12 21.888 126.57 15.65 6925.96 f3 48.0 49.0 19208.0 972.50 21.50 88.60 15.45 7272.31 f4 48.5 48.5 19014.0 1150.0 21.4095 105.84 11.15 5143.86 f5 48.5 48.5 19014.0 1075.0 12.514 98.94 14.08 6492.99 f6 48.0 49.0 19208.0 1288.75 19.932 117.42 Average value 112.12 Standard deviation 17.57 13.62 13.86 1.65 6410.03 6375.39 744.96 293 Abstract Table I.8.7 The results of static bending test (May Khe Foy) No B mm H mm Sx mm3 Load kgf Deflection mm Bending Strength MPa Modulus Of elasticity GPa Stiffness N.m2 g1 48.5 49.0 19408.1 1449.37 21.0795 130.69 16.78 7979.04 g2 48.5 50.0 20208.3 1348.75 19.8995 116.80 15.69 7930.45 g3 47.0 48.5 18425.9 1300.0 19.793 123.47 15.71 7020.21 g4 48.0 50.0 20000.0 1351.25 21.820 118.23 13.58 6791.69 g5 47.0 49.0 18807.8 1308.12 22.4025 121.72 15.74 7255.88 g6 47.5 50.0 19791.6 1291.25 22.6735 114.17 Average value 120.85 Standard deviation 5.87 13.02 15.09 1.46 6441.75 7236.50 617.99 Table I.8.8 The final values of static bending test (Seven types of wood) No Wood Bending Strength MPa STDV STDV Stiffness N.mm2 STDV 15.02 Modulus Of elasticity GPa 13.97 a May Deng 116.33 1.25 6484.92 851.47 b May Tai 86.33 18.80 10.40 2.34 4954.46 1272.6 c May Dou 104.20 20.13 14.59 2.67 6683.51 1297.8 d May Nhang 76.86 17.07 9.97 2.58 4481.81 1572.2 e May Ken Heua 87.11 4.48 9.77 2.83 4143.54 1541.9 f May Khen Hine 112.12 17.57 13.86 1.65 6375.39 744.96 g May Khe Foy 120.85 5.87 15.09 1.46 7236.50 617.99 294 [...]... Typical mechanical properties of seven types of wood 63 Table 5.3 Typical mechanical properties of seven types of wood 64 Table 5.4 Strength and stiffness of hardwoods in relation to weight density 65 Table 5.5 Strength and stiffness of softwoods in relation to weight density 66 Table 5.6 Comparison of mechanical properties of Laos woods and some US woods 67 Comparison of mechanical properties of Laos woods... have done in the area of wood testing and the test methods for evaluation wood properties The two parts of this review are shown in the following sections 2.1 Literature review on work done on wood testing Bao et al [2] conducted experiments to study the intrinsic differences in various wood properties between juvenile wood and mature wood in China They also considered the differences in wood properties. .. conducts of sap in addition to serving as structural elements, as for example in pine (May Pek, May Nhang, etc.) The softwood tree is illustrated in Figure 3.2 Some hardwoods are truly hard whereas others can be softer than softwoods Figure 3.3 and Figure 3.4 show the differences in internal structure between softwood and hardwood and the variation in properties in different directions The structure of softwood... machining of wood by cutting, which is a demanding technological process because of wood s specific structure Next, this study focused on the structural and mechanical properties of wood with outcome of the cutting process Finally, 21 Chapter 5 Results and discussion their work was intended to show the experimental results as regard to the wood strength in two different directions of wood cutting The... related to analysis of the wood strength in eight tests on seven types of wood from Laos Woods which were used for this project are derived from a region of warm climate in the middle part of the country (Vientiane province) Wood in other parts will be tested in the future for comparison with the values obtained in this study At the present time, wood from natural forests has declined considerably and... from each of seven different species of wood to determine their mechanical properties and physical properties Seven types of wood are: May Deng, May Tai, May Dou, May Nhang, May Khen Heua, May Khen Hine and May Khe Foy A total of 336 specimens (dry condition) have been tested for seven strength and two physical properties In this project, the specimens of each wood were made from only one piece of timber... a range of the Laos wood strength values when compared with other wood in other countries In the past, the strength properties of Laos wood have not been reported and provided yet In addition, this information may help us to determine the value and use of the wood in a variety of construction or in markets This project will also be of benefit to the researcher’s faculty or country for carrying on with... other wood from other areas, eg Incense cedar, eastern and western red cedar, ponderosa pine and Douglas fir 22 Chapter 5 Results and discussion The strength properties of some commercially important woods grown in the United States are given in the Handbook -wood [6] The strength values of sixty seven hardwoods and twenty nine softwoods, in static bending, impact bending, compression parallel to grain,... testing of wood in other areas of the country when the project had been accepted The main important purpose of this project is an analysis of the test results of mechanical properties for wood application, the manner in which the specimens break and the comparison of wood strengths with some popular woods of USA such as hardwoods: Locus (black), Hickory (pecan), Maple (sugar), and Oak (swamp white); softwoods:... purposes, such as lumber, beams, doors, windows, light framing, siding, exterior finish, interior finish, frames, roofing, flooring, sub-flooring, parquet, furniture, fencing, packaging The principal woods used in this study and their cost are shown in Table 3.1 Softwoods are commonly used for construction, because they are cheaper and easier to work with Some hardwoods are used for non-construction products ... stiffness of softwoods in relation to weight density 66 Table 5.6 Comparison of mechanical properties of Laos woods and some US woods 67 Comparison of mechanical properties of Laos woods and some US woods... Table 5.2 Typical mechanical properties of seven types of wood 63 Table 5.3 Typical mechanical properties of seven types of wood 64 Table 5.4 Strength and stiffness of hardwoods in relation to weight... beams, doors, windows, light framing, siding, exterior finish, interior finish, frames, roofing, flooring, sub-flooring, parquet, furniture, fencing, packaging The principal woods used in this study