Phased evaluation method for acoustic performance of flute bamboo based on multi-index combination

Abstract

The present application relates to the technical field of musical instrument material evaluation, and provides a flute bamboo acoustic performance phased evaluation method based on multi-index combination. The method comprises the following steps: obtaining sample data and performing sample identification and classification; performing phased primary screening to enter acoustic testing or preliminary elimination suggestion; obtaining silicon dioxide content, obtaining silicon dioxide adaptation grade and score; performing acoustic actual measurement correction, calculating evaluation score, and obtaining grading standard. The method realizes stable grading across production areas, bamboo species and batches.

Description

Technical Field

[0001] This invention relates to the field of musical instrument material evaluation technology, and in particular to a method for phased evaluation of the acoustic performance of bamboo flute material based on a combination of multiple indicators. Background Technology

[0002] Bamboo flute making has long relied on flute makers' experience in selecting materials based on appearance, feel, and sound when struck. Evaluation results are heavily influenced by individual experience, making it difficult to achieve stable grading across production areas, bamboo species, and batches. Existing bamboo testing methods primarily serve the performance analysis of structural timber, papermaking timber, or general materials, lacking a comprehensive evaluation process specifically for bamboo flute making. In particular, there is a lack of dedicated evaluation procedures for flute-grade bamboo, a mechanism for determining silica ranges, and a rapid screening method for predicting elastic modulus based on density. Summary of the Invention

[0003] In view of this, the present invention provides a phased evaluation method for the acoustic performance of bamboo flute materials based on a combination of multiple indicators, so as to achieve stable grading across production areas, bamboo species and batches.

[0004] In a first aspect, the present invention provides a method for phased evaluation of the acoustic performance of bamboo materials for flutes based on a combination of multiple indicators, the method comprising:

[0005] Step 1: Obtain sample data and perform sample identification and classification; Step 2: Conduct a phased primary screening based on Step 1 to determine whether candidates will proceed to acoustic testing or receive preliminary elimination recommendations. Step 3: Obtain the silica content based on Step 2 to get the silica compatibility level and score; Step 4: Perform acoustic measurement and correction according to Step 3, calculate the evaluation score, and obtain the grading standard.

[0006] Optionally, step 1 includes: A basic database of 18 bamboo samples was obtained. The bamboo sample and chemical database includes bamboo species, origin, age, cellulose, hemicellulose, lignin, crystallinity, and silica of flute-making bamboo, which are used to support the combination of indicators and interval determination. Among them, 6 samples are complete acoustic sample data, including complete density, dynamic elastic modulus E1, specific elastic modulus E / rho, acoustic radiation quality constant R, acoustic impedance w, and silica, which are used to support the main density screening. The remaining 12 samples are supplementary data, including existing chemical and silica data, density and acoustic vibration parameters to be supplemented, which are used for subsequent model improvement.

[0007] Optionally, the primary screening in step 2 includes density ρ and dynamic elastic modulus E1; density ρ is used as a rapid screening index; dynamic elastic modulus E1 is used as the core acoustic measurement index to reflect the vibration stiffness of bamboo; in the 6 complete acoustic sample data, the in-sample R² of the mean of density ρ and dynamic elastic modulus E1 is about 0.729, which is used as the basis for the primary screening.

[0008] Optionally, step 3 includes: The silica is used as an auxiliary indicator for the range, which is used to assist in the judgment of hardness, processability, wear resistance and tone tendency. Establish the following rules for determining silica: do not use linear scoring, set an appropriate range, and ensure that the range can be updated; The silica content is determined using a range-based compatibility assessment. When the silica content is between 0.90% and 1.20%, the compatibility grade is excellent, with a compatibility score of 100. The hardness and processing compatibility are relatively balanced, and this range is considered the preferred range. When the silica content is between 0.80% and 0.90% or between 1.20% and 1.30%, the compatibility grade is good, with a compatibility score of 80. At this point, the material is either too soft or too hard, and the assessment is based on the specific elastic modulus E and the intended use. When the silica content is less than 0.80% or greater than 1.30%, the compatibility grade is poor, with a compatibility score of 60. At this point, the material is either too soft or too hard and is not suitable as a high-grade flute material.

[0009] Optionally, step 4 includes: The evaluation score adopts a combination of elastic modulus as the primary factor and silica range as the secondary factor. If the measured dynamic elastic modulus E is available, the measured dynamic elastic modulus E is used first. If there is no measured data, the density prediction E_pred is used for rapid screening. The dynamic elastic modulus score E_score is: E_score = min(120, 100 × E / E_ref); Among them, E_ref is determined based on the statistical analysis of the benchmark sample, where E_ref = 14.0 GPa and E is the measured dynamic elastic modulus; if there is no measured condition, the density prediction E_pred is used as a substitute. Si_score for silica adaptation: 100, 80 or 60 depending on the silica range; The acoustic potential score P is: P = α × E_score + β × Si_score Among them, α = 0.75 and β = 0.25.

[0010] Optionally, step 4 further includes: The following grading rules are established: E_score weight is 0.75, Si_score weight is 0.25, E_ref=14.0 Gpa, and P≥85 is considered excellent; When P≥85, the grade is excellent and it is used as a candidate material for high-quality performance bamboo flutes; when 60≤P<85, the grade is qualified and it is used as a material for ordinary practice flutes or general products; when P<60, the grade is unqualified and it is not used for bamboo flute making.

[0011] In a second aspect, embodiments of the present invention provide a computer-readable storage medium comprising a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to execute the phased evaluation method for acoustic performance of bamboo flutes based on a combination of multiple indicators, as described in the first aspect or any possible implementation thereof.

[0012] Thirdly, embodiments of the present invention provide an electronic device, including: one or more processors; a memory; and one or more computer programs, wherein the one or more computer programs are stored in the memory, and the one or more computer programs include instructions that, when executed by the device, cause the device to perform the phased evaluation method for acoustic performance of bamboo flutes based on a combination of multiple indicators, as described in the first aspect or any possible implementation of the first aspect.

[0013] The technical solution provided by this invention includes acquiring sample data and classifying the samples; conducting phased main screening to enter acoustic testing or make preliminary elimination recommendations; acquiring the silica content to obtain the silica compatibility level and score; performing acoustic measurement correction, calculating the evaluation score, and obtaining the grading standard. This method achieves stable grading across production areas, bamboo species, and batches. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 The flowchart illustrates a method for phased evaluation of the acoustic performance of bamboo flutes based on a combination of multiple indicators, as provided in an embodiment of the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms “a,” “the,” and “the” used in the embodiments of this invention are also intended to include the plural forms unless the context clearly indicates otherwise.

[0018] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0019] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0020] Figure 1 The flowchart of the phased evaluation method for the acoustic performance of bamboo flute materials based on a combination of multiple indicators provided in the embodiments of the present invention is as follows: Figure 1 As shown, the method includes: Step 1: Obtain sample data and perform sample identification and classification; In this embodiment of the invention, step 1 includes: A basic database of 18 bamboo samples was obtained. The bamboo sample and chemical database includes bamboo species (e.g., Jiangxi bitter bamboo, Guangxi spotted bamboo, Anhui purple bamboo, and Zhejiang spotted bamboo), origin, age, cellulose, hemicellulose, lignin, crystallinity, and silica, which are used to support the combination of indicators and interval determination. Among them, 6 samples are complete acoustic sample data, including complete density, dynamic elastic modulus E1, specific elastic modulus E / rho, acoustic radiation quality constant R, acoustic impedance w, and silica, which are used to support the primary density screening. The remaining 12 samples are supplementary data, including existing chemical and silica data, density and acoustic vibration parameters to be supplemented, which are used for subsequent model improvement.

[0021] Step 2: Conduct a phased primary screening based on Step 1 to determine whether candidates will proceed to acoustic testing or receive preliminary elimination recommendations. In this embodiment of the invention, the staged main screening in step 2 includes density ρ and dynamic elastic modulus E1; density ρ is used as a rapid screening index, which has the characteristics of convenient detection, low cost and suitability for field application; dynamic elastic modulus E1 is used as the core index of acoustic measurement, which is used to reflect the vibration stiffness of bamboo and has high accuracy; in the 6 complete acoustic sample data, the in-sample R2 of the mean of density ρ and dynamic elastic modulus E1 is about 0.729, which is used as the basis for staged main screening.

[0022] Step 3: Obtain the silica content based on Step 2 to get the silica compatibility level and score; In this embodiment of the invention, step 3 includes: The silica is used as an auxiliary indicator for the range, and it is not advisable to use a linear score that is better the higher it is. Its role is to assist in the judgment of hardness, processability, wear resistance and tone tendency. The following rules were established for determining silica content: linear scoring was not used, and an adaptation range was set that can be updated. Linear scoring was not used because experiments showed that samples with excessively high silica content (such as JK 2-2, 1.46%) had a higher elastic modulus but were more difficult to process and had a harder tone. An adaptation range was set because samples with silica content of around 1% (such as ZB 1-1, 0.93%) had a relatively balanced hardness and processability. The ability to update the range is to reserve space for subsequent sample expansion and standard optimization.

[0023] The silica content is determined using a range-based compatibility assessment to avoid simply equating high silica content with high acoustic performance. When the silica content is in the range of 0.90%-1.20%, the compatibility grade is excellent, with a compatibility score of 100. Hardness and processing compatibility are relatively balanced, and this range is considered the preferred range. When the silica content is in the range of 0.80%-0.90% or 1.20%-1.30%, the compatibility grade is good, with a compatibility score of 80. At this point, the material is either too soft or too hard, and the assessment is based on the specific elastic modulus E and the intended use. When the silica content is less than 0.80% or greater than 1.30%, the compatibility grade is poor, with a compatibility score of 60. At this point, the material is either too soft or too hard and is not suitable as a high-end flute material. The above ranges are the current working ranges and can be further updated as the benchmark sample library expands, flute manufacturing tests are conducted, and performance evaluations are performed.

[0024] In this embodiment of the invention, explanatory indicators are used to explain the chemical composition of cellulose, hemicellulose, lignin, and crystallinity, and to explain stiffness, damping, material differences, and regional differences. These indicators are not the sole basis for judgment at present; they are used to explain differences in material structure and subsequent model calibration. Given the current limited number of complete acoustic samples, it cannot be concluded that they have formed a stable and significant independent predictive contribution, and further verification with more samples is needed.

[0025] Step 4: Perform acoustic measurement and correction according to Step 3, calculate the evaluation score, and obtain the grading standard.

[0026] In this embodiment of the invention, step 4 includes: Acoustic calibration parameters: specific elastic modulus E / ρ, acoustic radiation quality constant R, and acoustic impedance ω; these parameters are used for subsequent reinforcement models and can support more refined evaluation of acoustic efficiency, acoustic radiation capability, and sound propagation characteristics.

[0027] The evaluation score adopts a combination of elastic modulus as the primary factor and silica range as the secondary factor. If the measured dynamic elastic modulus E is available, the measured dynamic elastic modulus E is used first. If there is no measured data, the density prediction E_pred is used for rapid screening. The dynamic elastic modulus score E_score is: E_score = min(120, 100 × E / E_ref); Among them, E_ref is determined based on the statistical analysis of the benchmark sample, where E_ref = 14.0 GPa and E is the measured dynamic elastic modulus; if there is no measured condition, the density prediction E_pred is used as a substitute. Si_score for silica adaptation: 100, 80 or 60 depending on the silica range; The acoustic potential score P is: P = α × E_score + β × Si_score Among them, α = 0.75 and β = 0.25.

[0028] In this embodiment of the invention, step 4 further includes: Grading rules are established as follows: the dynamic elastic modulus score (E_score) has a weight of 0.75, as dynamic elastic modulus is a core factor affecting acoustic performance; the Si_score has a weight of 0.25, as silica is used as an auxiliary indicator and should not excessively influence the evaluation results; E_ref = 14.0 GPa, based on the statistical median of high-quality bamboo flute scraps; P ≥ 85 is considered excellent, corresponding to a combination with E ≥ 14.0 and good silica compatibility. When P≥85, the grade is excellent, and it is used as a candidate material for high-quality performance bamboo flutes. The recommended treatment is to enter the flute-making verification and fine processing process. When 60≤P<85, the grade is qualified, and it is used as a material for ordinary practice flutes or general products. The recommended treatment is to select its use based on appearance, defects, and tonal requirements. When P<60, the grade is unqualified, and it should not be used for bamboo flute making. The recommended treatment is to repurpose it or discard it.

[0029] In this embodiment of the invention, the adaptation rules are as follows: With application-adaptive design, the method of this invention incorporates sample number, origin, bamboo species, and commonly used flute-making tones into the output results, so that the evaluation results not only give a grade of excellence, but also provide application-adaptive suggestions, as shown in Table 1.

[0030] Table 1 Application Adaptation Design ; The application-adaptation logic does not treat application-adaptation as a mandatory rule, but rather as additional output information; the application-adaptation is based on historical sample statistics and flute makers' experience, and can be updated as data accumulates; this method reflects the evaluation differences between different origins of the same bamboo species and between different bamboo species of the same origin.

[0031] In this embodiment of the invention, the embodiment data is as follows: The sample data, as shown in Table 2, is based on six complete acoustic samples at this stage and is used to demonstrate that the evaluation process can be run on real samples. This embodiment does not present the current sample size as a final standard, but only to support the feasibility of the method.

[0032] Table 2 Sample Data ; The method of this invention can simultaneously provide the elastic modulus level, silica range adaptation results, overall grade, and recommendations for flute manufacturing applications. For samples with high silica content but high E value, the method does not simply deny their acoustic potential, but rather indicates processing difficulty or a risk of a harsh tone; for samples with low E value but silica content close to the adaptation range, the method of this invention can provide a judgment of whether it is acceptable or requires further verification.

[0033] Analysis of the embodiments shows that the method of the present invention can simultaneously provide: elastic modulus level (E_score); silica range adaptation result (Si_score); overall grade (P-value classification); and recommendations for flute manufacturing applications (adaptation application). Special cases are handled as follows: For samples with high silica but high E-score (e.g., JK 2-2), the approach is not to simply deny acoustic potential, but to indicate processing difficulty or a risk of a harsh tone; for samples with low E-score but silica close to the adaptation range, the approach is to provide a judgment of either "qualified" or "requiring further verification." Method validation is shown in Table 3, which compares the grade determination of the 6 samples with the actual acceptance by flute makers.

[0034] Table 3 Comparison of Level Assessment and Actual Recognition by Flute Makers ; Verification conclusion: The grading method of this invention is basically consistent with the actual acceptance by flute makers. In particular, for JK 2-2, which has high silica content but a high E value, this invention does not simply deny its acoustic potential due to the high silica content. Instead, it retains the excellent grade assessment through the E_score and uses silica as an auxiliary evaluation tool to indicate processing risks. This is precisely the advantage of this invention's method over the single-index scoring method.

[0035] The method of this invention includes a five-level comprehensive evaluation process: integrating sample identification, density screening, silica range assistance, chemical interpretation, and acoustic correction into a complete process; a silica range determination mechanism: transforming silica from a single content index into a suitable range index (0.90%-1.20% is excellent), avoiding the erroneous evaluation that higher is always better; a density primary screening mechanism: using density as a low-cost, rapid, and on-site applicable first screening index, and allowing the use of density to predict dynamic elastic modulus; grading rules: forming excellent, qualified, and unqualified flute-making material grades through E_score, Si_score, and P value (α=0.75, β=0.25); and suitable application output: combining bamboo species, origin, number prefix, and common key to output material suggestions suitable for different bamboo flute making needs.

[0036] Compared with the prior art, the present invention has the following advantages: Evaluation criteria: Existing technologies rely on the subjective experience of flute makers (looking at the bamboo, listening to the bamboo) or a single physical indicator. This invention provides a comprehensive evaluation based on measurable physical and chemical indicators. The existing technologies for silicon dioxide treatment methods either do not incorporate them or simply add linear values. This invention uses a range-fitting determination to avoid the situation where higher is always better. The evaluation process is different from the existing technology which has a dedicated process for bamboo materials used in flutes. This invention has a five-level progressive evaluation process. The existing grading standards rely on personal experience and judgment, while this invention uses quantitative scoring and P-value grading. Application output: Existing technologies do not provide application output; this invention provides bamboo species-origin-tone adaptation suggestions.

[0037] This invention's method detects the natural chemical components of bamboo, not added substances; focuses on acoustic performance evaluation, not mechanical flexibility; establishes the correlation between chemical components and acoustic performance; transforms the selection of bamboo for flutes from experience-based judgment into a detectable, calculable, and verifiable technical process; uses density or dynamic modulus of elasticity as the main indicator of acoustic potential; transforms silica content from a simple content description into a range-fit judgment; uses chemical components such as cellulose, lignin, and crystallinity as the basis for interpretation and correction; and finally outputs grading results and usage suggestions suitable for bamboo flute making.

[0038] The technical solution provided by this invention includes acquiring sample data and classifying the samples; conducting phased main screening to enter acoustic testing or make preliminary elimination recommendations; acquiring the silica content to obtain the silica compatibility level and score; performing acoustic measurement correction, calculating the evaluation score, and obtaining the grading standard. This method achieves stable grading across production areas, bamboo species, and batches.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for phased evaluation of the acoustic performance of bamboo materials for flutes based on a combination of multiple indicators, characterized in that, The method includes: Step 1: Obtain sample data and perform sample identification and classification; Step 2: Conduct a phased primary screening based on Step 1 to determine whether candidates will proceed to acoustic testing or receive preliminary elimination recommendations. Step 3: Obtain the silica content based on Step 2 to get the silica compatibility level and score; Step 4: Perform acoustic measurement and correction according to Step 3, calculate the evaluation score, and obtain the grading standard.

2. The method according to claim 1, characterized in that, Step 1 includes: A basic database of 18 bamboo samples was obtained. The bamboo sample and chemical database includes bamboo species, origin, age, cellulose, hemicellulose, lignin, crystallinity, and silica of flute-making bamboo, which are used to support the combination of indicators and interval determination. Among them, 6 samples are complete acoustic sample data, including complete density, dynamic elastic modulus E1, specific elastic modulus E / rho, acoustic radiation quality constant R, acoustic impedance w, and silica, which are used to support the main density screening. The remaining 12 samples are supplementary data, including existing chemical and silica data, density and acoustic vibration parameters to be supplemented, which are used for subsequent model improvement.

3. The method according to claim 2, characterized in that, The primary screening in step 2 includes density ρ and dynamic elastic modulus E1; density ρ is used as a rapid screening index; dynamic elastic modulus E1 is used as the core acoustic measurement index to reflect the vibration stiffness of bamboo; in the 6 complete acoustic sample data, the in-sample R² of the mean values ​​of density ρ and dynamic elastic modulus E1 is approximately 0.729, which serves as the basis for the primary screening.

4. The method according to claim 3, characterized in that, Step 3 includes: The silica is used as an auxiliary indicator for the range, which is used to assist in the judgment of hardness, processability, wear resistance and tone tendency. Establish the following rules for determining silica: do not use linear scoring, set an appropriate range, and ensure that the range can be updated; The silica content is determined using a range-based compatibility assessment. When the silica content is between 0.90% and 1.20%, the compatibility grade is excellent, with a compatibility score of 100. The hardness and processing compatibility are relatively balanced, and this range is considered the preferred range. When the silica content is between 0.80% and 0.90% or between 1.20% and 1.30%, the compatibility grade is good, with a compatibility score of 80. At this point, the material is either too soft or too hard, and the assessment is based on the specific elastic modulus E and the intended use. When the silica content is less than 0.80% or greater than 1.30%, the compatibility grade is poor, with a compatibility score of 60. At this point, the material is either too soft or too hard and is not suitable as a high-grade flute material.

5. The method according to claim 4, characterized in that, Step 4 includes: The evaluation score adopts a combination of elastic modulus as the primary factor and silica range as the secondary factor. If the measured dynamic elastic modulus E is available, the measured dynamic elastic modulus E is used first. If there is no measured data, the density prediction E_pred is used for rapid screening. The dynamic elastic modulus score E_score is: E_score = min(120, 100 × E / E_ref); Among them, E_ref is determined based on the statistical analysis of the benchmark sample, where E_ref = 14.0 GPa and E is the measured dynamic elastic modulus; if there is no measured condition, the density prediction E_pred is used as a substitute. Si_score for silica adaptation: 100, 80 or 60 depending on the silica range; The acoustic potential score P is: P = α × E_score + β × Si_score Among them, α = 0.75 and β = 0.

25.

6. The method according to claim 5, characterized in that, Step 4 also includes: The following grading rules are established: E_score weight is 0.75, Si_score weight is 0.25, E_ref=14.0 Gpa, and P≥85 is considered excellent; When P≥85, the grade is excellent and it is used as a candidate material for high-quality performance bamboo flutes; when 60≤P<85, the grade is qualified and it is used as a material for ordinary practice flutes or general products; when P<60, the grade is unqualified and it is not used for bamboo flute making.

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