The Properties and Features of the Wood Material - Lab Report Example

Timber Test Lab Report al Affiliation The lab report generally comprises of an experimental set up that was aimedtowards determining various wood tests. This set-up was generally aimed towards enabling for computation of the maximum compression strength as well as the ultimate modulus of elasticity. The basic consideration was that; they all set basis on both parallel and perpendicularly aligned set-ups. The experimental procedure also enabled for identification of the general influence of both the wood type, failure mechanism, as well as the wood direction. The main factors under study in this lab test were on the aspects of the static bending as well as the ultimate compression of the given wood. The primary focus for undertaking this lab experiment was the fact that it is very essential to be conversant with various wood properties since it is a very vital construction element. On the other hand, wood is regarded as an anisotropic component. It is due to the fact that; its features tends to vary with respect to the wood’s grain structure. It hence necessitates for the utilization of various elastic constants. The variation often occurs on the basis of Radial, Longitudinal, as well as the Tangential faces as shown below: Introduction: Objectives The main objective of undertaking this lab experiment was to assist in providing a better understanding of the properties and features of the wood material. To ascertain with this ultimate aim, the experiment was done using four primary samples. It was based on the fact that; two of these samples were used for testing the compressive strength in such a manner that the load was aligned in a parallel position. The other two were also subsequently performed in such a manner that the load was aligned in a perpendicular position to the grains. This set-up was generally meant for enabling for computation of the maximum compression strength as well as the ultimate modulus of elasticity. The basic consideration was that; they all set basis on both parallel and perpendicularly aligned set-ups. The experimental procedure also enabled for identification of the general influence of both the wood type, failure mechanism, as well as the wood direction (New York Lumber Trade Association, 1923). Experimental Procedure: Static Bending A. Tangential In this segment, the lab experiment started by first taking the measurements of the width, Length, as well as the height of the beam specimen. After recording these dimensions, the beam’s mid-point was then marked alongside the member’s length. After it, the specimen was the mounted on the testing apparatus while ensuring that the bearing block is centered at the specimen’s midspan. Using the testing machine’s slow range’s slow speed, the entire beam was then loaded. The levels of deflections were then recorded accordingly after the proportion of about 100 pounds load. The beam was then loaded to the failure until its visibility is observed. All the results were then clearly recorded before analyzing them. B. Radial: The experimental procedure for this set-up resembled the one for the tangential set-up. The only difference emerged when it came to the aspect of computing and making the final analysis with regards to the results. Compression: A. Longitudinal (Stresses parallel to the grains) Here, the initial procedure was the act of measuring both the length as well as the cross-sectional area of the given test material. While doing this, it was placed in an upright position within the test machine. The specimen was then loaded with the testing machines cross head of about 0.005”/min until it reached the failure mode. The records were then made after a constant proportion of 1000 pounds load. The machine’s speed was the increased up to 0.2”/min, all the way from 0.1”/min. This was specifically done after the failure so as to bring out a clear and distinct view with regards to the failure mode. The results were then recorded accordingly before plotting a stress verses strain curve. B. Radial and Tangential (Stresses perpendicular to the grains) The widths and the bases of the specimen were initially measured accordingly. This was then followed by the act of computing the loading area through multiplication of both variables. The steel block was then used to apply the given load. This was entirely done until the indicator reached an ultimate point of around 0.1” with regards to the change in length. This hence enabled for determination of the loading area. The stress verses strain curve was the plotted as in part A. Results: Static Bending: Radial Length (wood) Height (h) Width (b) Length (arm) Length (Upper arm) Weight (lbs.) 17.875 1.44 1.43 16.625 5.625 0.578 Tangential Length (wood) Height (h) Width (b) Length (arm) Length (upper arm) Weight (lbs.) 17.75 1.47 1.45 16.625 5.625   Radial Load (lbs.) Deflection (Δx) Tangential Load (lbs.) Deflection (Δx) 100 0.028 100 0.046 200 0.054 200 0.064 300 0.105 300 0.081 400 0.129 400 0.099 500 0.154 500 0.117 600 0.181 600 0.134 700 0.208 700 0.152 800 0.237 800 0.17 900 0.27 900 0.193 1000 0.305 1000 0.211 1100 0.345 1100 0.235 Failure* 1235 0.365 1200 0.257 1300 0.284 1400 0.322 Failure* 1456 0.36 Graphical Presentation: Compression: Longitudinal Length (wood) Height (h) Width (b) Length (arm) Length Weight (lbs.) 2.921 1.416 1.451 16.625 5.625 0.096 Radial Length (wood) Height (h) Width (b) Length (arm) Length Weight (lbs.) 2.9 1.41 1.448 16.625 5.625 0.096 Radial Load (lbs.) Deflection (Δx) Longitudinal Load (lbs.) Deflection (Δx) 1000 0.011 2000 0.023 2000 0.03 3000 0.027 2700 0.115 4000 0.031 2800 0.167 5000 0.035 2900 0.217 6000 0.041 3000 0.251 7000 0.046 Failure* 3114 0.291 8000 0.051 9000 0.058 10000 0.074 Failure* 11185 0.08 Graphical Presentation: Longitudinal Radial: Discussion: The results obtained above brought in a clear view with regards to the wood properties. For instance, the ultimate wood property can be entirely determined through the computation of the Modulus of Rapture (MOR), as well as the Flexural Modulus of Elasticity (MOE) (American Society of Civil Engineers & United States, 1942). From the above results; MOR for the Radial= Mc/I M= 1235 C= 0. 365 I = (1.43×1.4/12 = 0.7276 Therefore; MOR = (1235 × 0.365)/ 0.7276 = 619.54 MOR for the Radial = (1456 × 0.36)/ 0.807 = 649.52 The results also show that; the amount of the exerted load is directly proportional to deflection. On the other hand, the results also indicated that there is a mutual correlation between the stress and strain. This was clearly shown in the two graphs above that are characterized with a curve that tends to increase gradually with increase in the stress levels. The results also confirmed that wood is actually much stronger towards its longitudinal direction. The longitudinal direction’s tensile strength tends to be larger as compared to the compressive strength when they act towards the same direction. In addition, it was realized that the longitudinal tensile strength is almost 40 times greater than the acting tensile strengths in either the tangential or radial directions (American Society of Civil Engineers & United States, 1942). Finally, it was noticed that the longitudinal compressive strength is often six times greater in either longitudinal or radial directions. Conclusion: The lab experiment generally dwelled on the main objective of providing a better understanding on the properties and features of the wood material. To ascertain with this ultimate aim, the experiment was done using four primary samples. It was based on the fact that; two of these samples were used for testing the compressive strength in such a manner that the load was aligned in a parallel position. The other two were also subsequently performed in such a manner that the load was aligned in a perpendicular position to the grains. Finally, the experimental procedure enabled for identification of the general influence of both the wood type, failure mechanism, as well as the wood direction. References: American Society of Civil Engineers., & United States. (1942). Timber test study: A work projects administration project. San Francisco, California. New York Lumber Trade Association. (1923). Report of Timber Test Committee. New York: Lumber Trade Association. Read More