GB/T 1936.2-2009Method for determination of the modulus of elasticity in static bending of wood (English PDF)

Foreword

GB/T 1936 is divided into two parts.

--- GB/T 1936.1 Wood bending strength test method;

--- GB/T 1936.2 Wood bending modulus of elasticity measurement method.

This section GB/T 1936.2 "Wood bending modulus of elasticity determination." this part of the international standard ISO 3349. 1975 "Wood static flexural modulus determination," the non-equivalent.

This Part replaces GB/T 1936.2-1991 "Wood bending modulus of elasticity determination." this section compared with the GB/T 1936.2-1991, the main changes are as follows.

--- Original standard 4.1 "load measurement accuracy should be consistent with GB/T 1928-1991 Chapter 6 requirements," the words "can be measured Load accuracy of 1% ";

--- Original standard "GB 1931 Chapter 3 test equipment specified in" 4.3, to "GB/T 1931-2009 the provisions of Chapter 3 Test Device "moisture content;

--- Added "Using a dial indicator or other instrument capable of measuring linear displacement measuring specimen deformation" in 6.2;

--- 6.3 times the deformation is measured by the "repeated four times" to "repeated three times," added "to the digital electronic control tester can be Loading rate was set at 1mm/min ~ 3mm/min ";

--- The 7.1 "based on a sample deformation values \u200b\u200bmeasured after three" to "the specimen deformation based on two measured value";

--- All the original standard "to accurately" to "accurate to";

--- The test records the table, "bending strength" and "moisture" two items removed.

Appendix A of this part is a normative appendix.

This part by the State Forestry Administration.

This part of the National Standardization Technical Committee centralized timber.

This section drafted by. China Forestry Science Institute of Wood Industry.

1 Scope

GB/T 1936 provisions of this part of the measuring timber flexural modulus of elasticity test equipment, samples, test procedures, and test results of the calculation report.

This section applies to wood unblemished MOE small sample measured.

2 Normative references

The following documents contain provisions which, through reference to GB/T 1936 to the present, constitute provisions of this section. For dated reference documents Member, all subsequent amendments (not including errata content) or revisions do not apply to this section, however, encouraged to reach under this section Parties to research agreement to use the latest versions of these documents. For undated reference documents, the latest versions apply to this section.

GB/T 1928-2009 physical and mechanical test methods - General GB/T 1929-2009 physical and mechanical test materials and test specimens sawing method GB/T 1931-2009 Method for determination of moisture content of wood Principle 3 in the proportional limit stress, according to the relationship between load and deformation of the timber to determine the flexural modulus of elasticity when force bent wood.

4 Test Equipment

4.1 Functional test load measurement accuracy of 1%. Supports of the radius of curvature of the end portion of the specimen ram apparatus is 30mm, two seat pitch Off should be 240mm.

Testing should be accurate measuring 4.2 to 0.1mm.

4.3 dial indicator range is 0mm ~ 10mm, accurate to 0.01mm.

4.4 GB/T 1931-2009 the provisions of Chapter 3 of the test device was measured moisture content.

5 Sample

5.1 test material sawing and test specimens shall conform to GB/T 1929-2009 the provisions of Chapter 3.

5.2 Sample size is 300mm × 20mm × 20mm, a length along the grain direction. Tone sample preparation requirements and inspection, the sample moisture content Whole shall conform to the provisions of GB/T 1928-2009 Chapter 3 and Chapter 4. Allow the bending strength test using the same sample, measured first bomb Modulus, flexural strength after the test.

6 Test procedure

6.1 using tangential loading, in the center of the sample length measured radial dimension of width, height tangential to the nearest 0.1mm.

6.2 loading two o'clock, with a dial indicator or other specimen deformation measurement instrument can measure the linear displacement of the test apparatus shown in Figure 1.