Design of an Acoustic-Based Nondestructive Test (NDT) Instrument to Predict the Modulus of Elasticity of Wood
Open accessAbstract
Modulus of elasticity (E) can predict the mechanical characteristics, as well as grade the quality of wood. The Destructive Test (DT) method is the more commonly used, where the wood sample is split up when being tested. This research used the NDT method based on the longitudinal stress wave method (LSWM) whilst utilizing handheld instruments. The calculated E-dynamic (Ed) from the NDT method was compared with the E-static (Es) from the DT method to validate the technique. Six different wood types were tested with ten samples of each kind. An average R-value of 0.898 was obtained, indicating a high correlation between the Ed values and Es values. The LSWM method requires reliable hardware and software to record the impulse response. It starts by hitting the wood with a hammer to create an impulse, finding the resonance frequency (f0), and later calculating the Ed. A more practical and easy-to-use handheld mobile instrument was developed using a Raspberry Pi-2 microcomputer as the signal processor, an LCD touchscreen, a USB soundcard, and a dynamic microphone that covers 0.1-5kHz and -64 ± 3dB. An internal telecommunication system is provided to support measurements conducted at lumber mills. The software includes band-pass filtering of the recorded spectrum where the f0 is depicted. A time-domain envelope fitting is then applied to the filtered spectrum to obtain the R2envelope. A low R2envelope value indicates an inadequate impulse response, and therefore, the test should be redone.
AI snapshot
Written from the paper’s full text.
TL;DR
The paper designs and validates “MyWood,” a handheld acoustic nondestructive test instrument using the longitudinal stress wave method to predict the modulus of elasticity of wood. Across 60 samples from six wood types, dynamic Ed correlated with destructive Es (average R-value 0.898; per-type R² 0.57–0.95), and an envelope-fitting R² envl was introduced to flag poor impulse recordings.
Key findings
- The NDT Ed values correlated with destructive Es values: the abstract reports an average R-value of 0.898. Per-type R² values were Mahogany 0.95, Acacia 0.90, Munggur 0.90, Sukun 0.63, Teak 0.59, and Sonokeling 0.57; Fig. 3 reports R² = 0.827 for five wood types (50 samples).
- The f0 range across the 60 samples was 1041.90–1913.30 Hz. For the Mahogany #1 example, the estimated f0 was 1.48 kHz with a magnitude of -76.58 dB.
- The handheld instrument was specified for 800–4100 Hz; the dynamic microphone covered 100–5000 Hz, and the soundcard had an average magnitude of -11.86 dB. The implemented FFT algorithm performed well in single-frequency tests with no distortion and harmonics, with only small harmonics and ripple above 4.1 kHz.
- Envelope-fitting R² envl > 0.95 occurred in 73.33% of Mahogany runs, 63.33% Munggur, 60.00% Acacia, 56.67% Teak, 46.67% Sonokeling, and 43.33% Sukun. Woods with lower R² ed tended to have lower R² envl, and a weak envelope fit indicates noise and that the LSWM test should be retaken.
Methods
- Six wood types (Sukun, Munggur, Mahogany, Teak, Sonokeling, Acacia) were tested with ten samples each, totaling 60 samples; dimensions were 120 × 12 × 6 cm, and densities ranged from 400 to 900 kg/m³.
- The LSWM procedure tapped one end of the wood with a hammer, recorded the impulse response at the other end, identified the fundamental resonant frequency f0, and calculated Ed using Eq. (1); Ed was compared with Es obtained by destructive testing following ASTM D143-94.
- The instrument used a Raspberry Pi-2 with Raspbian, a USB soundcard, a dynamic microphone, and a 3.5-inch resistive touchscreen; software used Python with Scipy, Numpy, Tkinter, and Matplotlib. Signal processing included a 3rd-order Butterworth band-pass filter centered at estimated f0 ± 200 Hz and envelope fitting to obtain R² envl; FFT was validated with single-frequency and dual-frequency intermodulation distortion tests.
Limitations
- Stated in the paper: moisture condition varied and was intentionally neglected for all wood types; the authors note results might be related to both moisture and density and should be considered in future similar experiments.
- Evident from the text: the microphone frequency response declined in the 800–2700 Hz range with a sensitivity difference of ±15 dB, described as quite poor, though the authors argue it can be ignored for identifying the first peak response. Sonokeling had a weak correlation (R² = 0.57) and was excluded from the Fig. 3 comparison of five wood types.
Model-written summary. Check it against the paper before relying on it.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
0 of 10 cited sources checked · 0 supported · 0 flagged
- Findingown data
The semi-automatic NDT instrument for predicting E of wood, called MyWood, was successfully designed and implemented.
“A semi-automatic nondestructive evaluation instrument for predicting the E of wood called MyWood was successfully designed and implemented.”
Quote in the paperSubstantial claim- Rests on an assumption: The LSWM method requires reliable hardware and software to record the impulse response.
- Findingown data
Mahogany wood had the highest R2 between Ed and Es among the wood types.
“The Mahogany wood is the wood with the highest R 2 .”
Quote in the paperNot a substantial claim - Findingown data
The FFT test showed only small harmonics and ripple at frequencies higher than 4.1 kHz.
“There is only small harmonics and ripple in a frequency higher than 4.1kHz.”
Quote in the paperNot a substantial claim - Findingnone given
A more practical and easy-to-use handheld mobile instrument was developed using a Raspberry Pi-2 microcomputer, an LCD touchscreen, a USB soundcard, and a dynamic microphone covering 0.1-5 kHz and -64 ± 3 dB.
“A more practical and easy-to-use handheld mobile instrument was developed using a Raspberry Pi-2 microcomputer as the signal processor, an LCD touchscreen, a USB soundcard, and a dynamic microphone that covers 0.1-5kHz and -64 ± 3dB.”
Quote in the paperSubstantial claim- Rests on an assumption: The LSWM method requires reliable hardware and software to record the impulse response.
- Findingown data
Woods with higher R2ed have a higher occurrence of R2envl > 0.95.
“It can be concluded that woods with higher R 2 ed have a higher occurrence of R 2 envl > 0.95.”
Quote in the paperSubstantial claim
- Findingown data
The longitudinal stress wave data from the preliminary research produced R2envl, which indicates whether the LSWM data recording procedure should be redone or whether environmental noise occurred.
“The longitudinal stress wave data from the preliminary research were able to produce a vital parameter named as R 2 envl that indicates whether the data recording procedure of LSWM should be redo or occurrence of environmental noise.”
Quote in the paperSubstantial claim- Rests on an assumption: Noise in the LSWM signal is due to background noise, poor impulse sound from the hammer, and friction between the wood and the supporting system.
- Rests on an assumption: Wood is anisotropic and its recorded impulse signal may contain more than one frequency resonance.
- Findingown data
The comparison of Ed and Es for five wood types (50 samples) had an R2 of 0.827.
“Comparison between the Ed and Es values of 5 wood types (50 samples) with an R 2 of 0.827.”
Quote in the paperSubstantial claim - Findingown data
The instrument was able to accommodate any waveforms in the range 800-4100 Hz, which is within the frequency range of the wood's longitudinal resonant frequency.
“In the experiment, the instruments were able to accommodate any waveforms in a range of 800 -4100Hz, which is within the frequency range of the wood's longitudinal resonant frequency.”
Quote in the paperNot a substantial claim- Rests on an assumption: The LSWM method requires reliable hardware and software to record the impulse response.
- Findingown data
The R2 between Ed and Es for the six wood types was unrelated to their density, as shown by Munggur having the second-lowest density but the second-highest R2.
“The R 2 for all six wood types in Table 2 are unrelated with their density shown by the Munggur wood with the second-lowest density but having the second-highest R2 value between Ed and Es.”
Quote in the paperNot a substantial claim - Findingnone given
A novel method to indicate whether the LSWM test produced a weak longitudinal stress wave signal was successfully introduced.
“A novel method to indicate whether the test produced a weak longitudinal stress wave signal data from the LSWM was successfully introduced.”
Quote in the paperSubstantial claim- Rests on an assumption: Noise in the LSWM signal is due to background noise, poor impulse sound from the hammer, and friction between the wood and the supporting system.
- Rests on an assumption: Wood is anisotropic and its recorded impulse signal may contain more than one frequency resonance.
- Findingown data
The microphone and soundcard frequency response declined in the 800 Hz to 2700 Hz range with a sensitivity difference of ±15 dB.
“However, the frequency response declined in the 800Hz to 2700Hz range with a sensitivity difference of ± 15 dB, which is quite poor.”
Quote in the paperNot a substantial claim - Findingown data
The sensor system of the instrument was able to work in the desired frequency range of 800 Hz to 4100 Hz.
“This sensor system was able to work in the desired frequency range, which is 800Hz to 4100Hz.”
Quote in the paperSubstantial claim - Findingown data
The wood with high R2ed, i.e., Acacia, Munggur, Mahogany, tends to have an R2envl around 0.9.
“In contrast, the wood with high R 2 ed, i.e., Acacia, Munggur, Mahogany, tends to have an R 2 envl around 0.9.”
Quote in the paperSubstantial claim - Findingown data
The wood with a low R2ed, such as Sonokeling (R2ed = 0.57), tends to have a low R2envl.
“The wood with a low R 2 ed, such as the Sonokeling (R 2 ed = 0.57), tends to have a low R 2 envl.”
Quote in the paperSubstantial claim - Premisecitation
The fundamental frequency value is used to obtain Ed according to the formula Ed = 4 L^2 f0^2 ρ.
“The fundamental frequency (the lowest frequency with the highest magnitude) value is then used to obtain the Ed value, according to the formula [12]:”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [12]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Premisecitation
The tap method using an impulse sound was feasible for small beams and commercial size construction lumber in obtaining their Young's moduli.
“The tap method using an impulse sound was feasible not only for small beams but also for commercial size construction lumber in obtaining their Young's moduli [7].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [7]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Interpretationown data
The R2envl can be used to measure how well the recorded signal represents the longitudinal stress wave.
“The result has proven that the R 2 envl can be used to measure how well the recorded signal is in representing the longitudinal stress wave.”
Quote in the paperSubstantial claim - Interpretationreasoning
The sensitivity discrepancies of the microphone/soundcard can be ignored for identifying the first frequency peak of an impulse.
“However, since the aim is to identify the first frequency of the peak response of an impulse, this sensitivity discrepancies effect to the results can be ignored.”
Quote in the paperSubstantial claim - Premisecitation
The wood with higher density and stiffness passes longitudinal stress waves with greater velocity.
“The wood with higher density and stiffness passes longitudinal stress waves with greater velocity [13].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [13]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Premisecitation
The envelope fitting process encounters similar issues with the logarithmic decrement method.
“Though more accurate, the envelope fitting process encounters similar issues with the logarithmic decrement method [21].”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [21]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Interpretationreasoning
The most significant disadvantage of the destructive method is that the remaining wood sample can no longer be used since it has been intentionally broken apart during the test.
“The most significant disadvantage of the destructive method is that the remaining wood sample can no longer be used since it has been intentionally broken apart during the test.”
Quote in the paperSubstantial claim
- Classified as probably not a substantial claim. 17
- May combine two claims. 12
- The quote only partly states this claim. 3
Classified as probably not a substantial claim. May combine two claims. The quote only partly states this claim.
FindingreasoningThe instrument was designed to be semi-automatic and to calculate NDT results directly on its display.
“For maintaining the robustness and the mobility of the instrument, the instrument was designed to be able to calculate the NDT results directly on the instrument's display.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Findingown dataThe frequency range of f0 for the 60 samples studied was 1041.90 Hz to 1913.30 Hz.
“The frequency range of f0 of the 60 samples studied is also provided.The minimum and the maximum frequencies are 1041.90Hzand 1913.30Hz.”
Quote in the paperNot a substantial claimMay combine two claims.
Findingown dataThe soundcard performed well in the desired frequency range and had an average magnitude of -11.86 dB, so no adjustment was needed.
“No adjustment is needed for the soundcard since it performed well in the desired frequency range and has an average magnitude of -11.86 dB.”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Findingown dataThe square wave test showed slight distortion in both input and instrument readings.
“Similar results are shown on both readings of slight distortion for the square wave, as shown in Fig. 7(a) and (b).”
Quote in the paperNot a substantial claimMay combine two claims.
Findingown dataThe implemented FFT algorithm performed well with no distortion and harmonics in the single-frequency test.
“The first test shows that the implemented FFT algorithm is performed well with no distortion and harmonics.”
Quote in the paperNot a substantial claimThe quote only partly states this claim.
Findingown dataThe NDT method based on LSWM produced Ed values that correlated highly with Es values from destructive testing, with an average R-value of 0.898 across six wood types.
“An average R-value of 0.898 was obtained, indicating a high correlation between the Ed values and Es values.”
Quote in the paperSubstantial claimClassified as probably not a substantial claim.
Findingnone givenThe technique involves conventional LSWM with additional band-pass signal filtering centered at the resonant frequency and envelope fitting.
“The technique involves the conventional LSWM process with additional band-pass signal filtering with resonant frequency as the center frequency of the filter and the envelope fitting method.”
Quote in the paperSubstantial claimMay combine two claims.
Findingnone givenEach building block of the device-sound card, microphone, and FFT algorithm-performed well and was validated.
“Each building block of the device, i.e., the sound card, microphone, and the FFT algorithm, was well performed and validated.”
Quote in the paperSubstantial claim- Rests on an assumption: The LSWM method requires reliable hardware and software to record the impulse response.
The quote only partly states this claim.
Findingown dataFor the 60 wood samples tested, the R2 between Ed and Es varied by wood type, ranging from 0.57 for Sonokeling to 0.95 for Mahogany.
“Sonokeling Dalbergia latifolia Roxb.0.57 -Teak Tectona grandis L.f. 0.59 1300 -1738 Sukun Artocarpus altilis 0.63 1313 -1477 Acacia Acacia mangium 0.90 1201 -1616 Munggur Pithecolobium Saman Benth 0.90 1164 -1760 Mahogany Swietenia spp.0.95 1042 -1913”
Quote in the paperSubstantial claimClassified as probably not a substantial claim. May combine two claims.
InterpretationreasoningA weak correlation between the filtered signal and the exponential model indicates that a lot of noise is depicted in the signal, and the LSWM test should be retaken.
“Furthermore, if the R 2 of the envelope fitting shows a weak correlation between the filtered signal and the exponential model, there is a higher indicates that a lot of noise is depicted in the signal, and the LSWM test should be retaken.”
Quote in the paperSubstantial claim- Rests on an assumption: Noise in the LSWM signal is due to background noise, poor impulse sound from the hammer, and friction between the wood and the supporting system.
- Rests on an assumption: Wood is anisotropic and its recorded impulse signal may contain more than one frequency resonance.
Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
PremisecitationSonokeling (D. latifolia) and Mahogany (S. mahogany) had the best acoustical properties, ultrasonic wave velocity, and ratio of wood stiffness to wood density among the others.
“Sonokeling (D. latifolia) and Mahogany (S. mahogany) had the best acoustical properties, ultrasonic wave velocity, and ratio of wood stiffness to wood density among the others [10].”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [10]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
InterpretationreasoningThe experiment results might be related to both moisture and density because moisture condition varied and was intentionally neglected for all wood types.
“The moisture condition varied and intentionally neglected for all wood types.Hence, the experiment results might be related to both moisture and density.”
Quote in the paperNot a substantial claimClassified as probably not a substantial claim.
InterpretationreasoningThe LSWM test procedure needs improvement because the recorded impulse signal may contain unwanted frequency components and noise.
“Specific characteristics of the wood require one to inspect the unfiltered spectrum since it might consist of ripples with some unwanted frequency components.The LSWM test procedure, therefore, needs improvement.”
Quote in the paperSubstantial claim- Rests on an assumption: Noise in the LSWM signal is due to background noise, poor impulse sound from the hammer, and friction between the wood and the supporting system.
- Rests on an assumption: Wood is anisotropic and its recorded impulse signal may contain more than one frequency resonance.
Classified as probably not a substantial claim. May combine two claims.
Interpretationnone givenA low R2 envelope value indicates an inadequate impulse response, and therefore the test should be redone.
“A low R 2 envelope value indicates an inadequate impulse response, and therefore, the test should be redone.”
Quote in the paperSubstantial claim- Rests on an assumption: Noise in the LSWM signal is due to background noise, poor impulse sound from the hammer, and friction between the wood and the supporting system.
- Rests on an assumption: Wood is anisotropic and its recorded impulse signal may contain more than one frequency resonance.
Probably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationThe sampling theorem states that a bandlimited signal can be precisely reconstructed if sampled at a rate at least twice the maximum frequency component.
“The sampling theorem stated that a bandlimited signal could be precisely reconstructed if it is sampled at a rate at least twice the maximum frequency component in it.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [8]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Probably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationFor wood, nondestructive evaluation methods include static bending, transverse vibration, and longitudinal stress wave.
“For wood, there are some nondestructive evaluation methods, i.e., static bending, transverse vibration, and longitudinal stress wave [6].”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [6]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Classified as probably not a substantial claim. May combine two claims.
PremisecitationThe elasticity constant is a vital mechanical property parameter of wood and reflects the resistance to deformation under external forces.
“The elasticity constant is a vital mechanical property parameter of wood and reflects the resistance to deformation under external forces [5].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [5]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Probably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationThe destructive evaluation involves samples being destroyed as a representation of the whole population using a grading machine.
“The destructive evaluation involves some samples to be destroyed as a representation of the whole population member using a grading machine [6].”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [6]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
Interpretationown dataSince Mahogany wood has the highest R2ed, it is not surprising that the envelope of the filtered signal of mahogany follows the exponential form.
“Since the Mahogany wood is the wood with the highest R 2 ed in Table 2, it is not surprising if the envelope of the filtered signal of the mahogany follows the exponential form (see Fig. 10).”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Premisenone givenEnvelope fitting is widely used to determine damping from a free vibration curve.
“An envelope fitting is another approach which widely used to determine the damping from a free vibration curve.”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
PremisecitationIf energy loss is small compared to stored energy, the amplitude will not decrease very much in one cycle of free vibration, and the motion is very close to sinusoidal.
“If the energy loss is small compared to the stored energy, the amplitude will not decrease very much in one cycle of free vibration, and the motion is very close to being sinusoidal [20].”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [20]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
Study design and conductnone givenThe moisture condition varied and was intentionally neglected for all wood types.
“The moisture condition varied and intentionally neglected for all wood types.”
Quote in the paperNot a substantial claim
The paper relies on this without support.
The modulus of elasticity calculation, both static and dynamic, does not depend on the existence of a wood knot.
“The E calculation (both for Es and Ed) does not depend on the existence of a wood knot.”
The paper relies on this without support.
Noise in the LSWM signal is due to background noise, poor impulse sound from the hammer, and friction between the wood and the supporting system.
“Noises are due to the presence of background noise, a poor impulse sound produced by the tapper (hammer), and the sound from the friction between the wood and the supporting system.”
The paper relies on this without support.
Wood is anisotropic and its recorded impulse signal may contain more than one frequency resonance.
“Wood is an anisotropic material where the recorded impulse signal created by the tapping might have more than one frequency resonance.”
The paper relies on this without support.
Visual inspection is not accurate because wood from a tree used for lumber can vary and the properties of every tree are not homogeneous.
“This method is not accurate since the wood of a tree used for lumber can vary, and the properties of every tree are not homogeneous.”
The paper relies on this without support.
The quantitative method provides more accurate grading.
“The quantitative method provides more accurate grading.”
The paper relies on this without support.
The LSWM method requires reliable hardware and software to record the impulse response.
“The LSWM method requires reliable hardware and software to record the impulse response.”
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
Each contradiction between two passages listed here was confirmed by an independent check.
Reported sampling rate cannot capture the reported resonant frequencies
MajorA 1 kHz sampling rate has a Nyquist limit of 500 Hz. It cannot capture the reported fundamental resonant frequencies of 1041.90-1913.30 Hz without aliasing, contrary to the paper's description of those measurements.
“The sampling frequency and overall observation interval are equal to 1kHz and 3s, respectively [9].”
“The minimum and the maximum frequencies are 1041.90Hzand 1913.30Hz.”
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Relation Between Static and Dynamic Modulus of Elasticity of Wood
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Squeezed film damping measurements on a parallel-plate MEMS in the free molecule regime
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The Acoustical Properties of Indonesian Hardwood Species
Karlinasari, L., Baihaqi, H., Maddu, A., et al. (2012) · MAKARA of Science Series · doi:10.7454/mss.v16i2.1405 · Cited by 15 · see citing works
Squeezed film damping measurements on a parallel-plate MEMS in the free molecule regime
Mol, L., Rocha, L. A., Cretu, E., et al. (2009) · International Conference on Solid-State Sensors, Actuators and Microsystems · doi:10.1109/sensor.2009.5285840 · Cited by 9 · see citing works
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Flagged first, then by citations
Research works printed but not linked: 2
- J. G. Proakis and D. G. Manolakis, Digital Signal Processing: Principles, Algorithms, Applications, 3rd ed. Prentice Hall, 1996, vol. 3.
- A. V. Oppenheim, A. S. Willsky, and S. Hamid Nawab, Signal and System, 2nd ed. Prentice Hall, 1998.
Cited by
Sorted by citations
Prediksi Nilai Kuat Lentur Kayu Tropis Berdasarkan Nilai Modulus Elastis
Awaludin, A., & Wusqo, U. (2021) · Jurnal Ilmu dan Teknologi Kayu Tropis · doi:10.51850/jitkt.v18i1.542 · Cited by 5 · see citing works
Edukasi Pemeriksaan Mutu Kayu dan Bambu sebagai Bahan Konstruksi
Junaid, A., Firstania, A. A., & Sofyan, S. A. A. (2023) · Surya Abdimas · doi:10.37729/abdimas.v7i1.2654 · Cited by 1 · see citing works
Destructive and Nondestructive E-Rating of Red Maple Veneers
Belaidi, D., Mohammadabadi, M., França, F., et al. (2025) · Forest Products Journal · doi:10.13073/fpj-d-25-00015
- Authors
- Utami, S. S., Mappuji, A., Achmad, B., Awaluddin, A., Ayutyastuti, A., Luckyarno, Y. F., & Yanti, R. J.
- Affiliations
- Universitas Gadjah Mada (ID)
- Venue
- Engineering Journal
- Published
- 2020-11-30
- Volume
- 24
- Issue
- 6
- Pages
- 109
- ISSN
- 0125-8281 (ISSN-L)
- OpenAlex
- W3117948980
- Cited by
- 3
- References
- 12
- Citations by year
- 2025: 1 · 2023: 1 · 2021: 1
- FWCI
- 0.26
- Type
- journal article
- Language
- en
- Open access
- diamond
- doi.org
- Locations
- Engineering Journal (publishedVersion)
- Engineering Journal (Chulalongkorn University) (submittedVersion, cc-by-nc-nd)
- Funders
- Universitas Gadjah Mada
- Topics
- Physical Sciences › Engineering › Building and Construction › Wood Treatment and Properties
- Physical Sciences › Engineering › Mechanics of Materials › Ultrasonics and Acoustic Wave Propagation
- Physical Sciences › Engineering › Civil and Structural Engineering › Structural Engineering and Materials Analysis
- Keywords
- elastic modulus, wood, non-destructive testing, hand-held instrument, Raspberry Pi, resonant frequency, impulse response, timber grading
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