Study On Corn Straw Mechanics And Water Loss Characteristic Of Different Loading

The resource of corn straw is rich, and it has excellent properties of physical and chemical, development potential is more and more attention by people. The moisture content is high after picking ear during harvest of corn straw, the straw stalk epidermis is tenacious, thick and dense, hinders the moisture evaporation inside the straw, straw moisture content is not suitable for recycling and baling straw over a long period of time, Straw baling is easy to get a package, storage is easy to rot, so it brings difficulties for straw harvest of reuse. On the basis of these characteristics, I study adjusting material device for corn straw, it can fracture, broke skin, crack node, and it can speed up to reduce the straw moisture content to be easy to recycle. The key component of adjusting material device is adjusting material roller that its design will affect adjusting material effect and adjusting material power consumption.Preliminary experiments on corn straw adjusting material process had been analyzed, had g ot the way of load during corn straw adjusting material process by using high speed photograp hy technology, Single-point pressure, three-point bending, shearing and torsion knead test of cor n straw were studied, to explore the destruction mechanism of straw by loads, constitutive equa tion and failure theory of corn straw were studied. The comprehensive comparison of the waterloss rate and power consumption is to evaluate straw adjusting material effect in different load ing ways. The main research contents of this paper is as follows:(1)Constitutive equation and failure theory of corn strawBased on the basic structure of corn straw, I got the basic equations of elasticity of corn straw, established model of straw constitutive equation and laid the foundation to the research of the failure theory of corn straw.(2)Single-point pressure, three-point bending test study of corn strawSingle-point pressure, three-point bending test of corn straw was done on the universal testing machine. Single factor experiment for three-point bending was done with different spans, different varieties, different sampling positions and different moisture contents, single factor experiment for single-point pressure was done with different sampling positions and loading methods, three factors five levels test was done with sampling position, loading speed and span as factors. The test results showed that: load and power consumption was the minimum, loading speed had no influence on the load and power consumption, when span is 80 mm for the single factor experiment for three-point bending, load and power consumption of corn straw decreased with the increase of sampling positions, load and power consumption had differences between varieties; power consumption and load was the minimum when loading speed was 20 mm/min, span was 80 mm, sampling location was at the top of the sampling position about the three-point bending orthogonal test; load and power consumption decreased with the increase of sampling positions, about single-point pressure test, load and power consumption of the sample is greater than the internodes, load and power consumption of the sample is less in longer axis than in short axis.(3)Shearing test study of corn strawShearing test of corn straw was done by homemade torsion fixture on the universal testing machine. Single factor experiment was done with different sampling positions and load parts. The test results showed that: load, power consumption and intensity of shearing test decreased with the increase of sampling positions, shearing capacity reduced with the decrease of the diameter size of corn straw.(4)Torsion test study of corn strawTorsion test study of corn straw was done by torsion test machine. I set the control system of torsion speed and realized constant loading torsion test. The test results showed that: torsion angle range of straw destroyed 70°-91°, torque range 7.95Nm-11.01 Nm, destroy the power consumption range 6.9773 J-12.0451 J.(5)Water loss rate test of corn strawWater loss rate was studied and carried on the comparison and analysis after three to seven days of the test about single-point pressure, three-point bending, shearing, torsion test study of corn straw and the matched group. The test results showed that: water loss rate order from big to small was torsion, single-point pressure, three-point bending, shearing, the state of nature. Under the torsion load, the water loss rate of corn straw was bigger than the other loading ways.