GB/T 41777-2022 in English
VALIDForensic sciences—Examination methods for explosive strength
- Issued on:2022-10-12
- Implemented on:2023-02-01
- File Format:PDF
- Delivery:Via email within 1~3 business days
$156.00
《GB/T 41777-2022法庭科学 爆炸物爆炸威力检验方法》由TC179（全国刑事技术标准化技术委员会）归口，TC179SC9（全国刑事技术标准化技术委员会痕迹检验分会）执行，主管部门为公安部。
Introduction
Analysis of the core content of the standard
This standard specifies the technical framework for the power inspection of explosives in the field of forensic science, focusing on three core modules:
| Inspection stage | Technical method | Key formulas |
|---|---|---|
| Identification of explosives | Refer to GB/T41845 | - |
| TNT equivalent calculation | Equivalent coefficient method | WTNT=λWEXP |
| Shock wave overpressure calculation | Air free field model | Δp=0.8433WTNT/R+2.7WTNT2/3/R2+7.3WTNT/R3 |
Detailed explanation of TNT equivalent coefficient
Table 1 in the standard lists the equivalent coefficients of 21 types of explosives, among which:
- Benchmark material: TNT's own coefficient is 1.0
- High explosives: Military explosives such as RDX (1.28) and TPX (1.26) have coefficients > 1.2
- Industrial explosives: Emulsion explosives (0.76), water gel explosives (0.73) and other coefficients are 0.7-0.8
- Special instructions: Pyrotechnics need to adjust the coefficient according to the chlorate content (0.35-0.65)
Key points for damage assessment implementation
Case simulation: 100g RDX (RDX) explosion power assessment:
- Look up the table to get λ=1.28, calculate WTNT=0.1×1.28=0.128kg
- Substitute into the overpressure formula to get Δp=0.3kg/cm² when R=2.15m
- Compare to Table 2 to determine that people at this distance will have hearing organ damage
Analysis of standard technology evolution
| Version Features | GB/T41777-2022 | International Similar Standards |
|---|---|---|
| Scope of Application | ≥30gTNT equivalent | Usually no lower limit |
| Damage Grading | Grade 4 (mild to extremely severe) | ASTM is divided into 5 grades |
| Calculation Formula | Third-order Polynomial Model | Brode formula is mostly used |
Test Conclusion Specification
According to clauses 6.1-6.2 of the standard, the conclusion statement needs to be distinguished:
- Bare explosive/soft packaging: clarify the scope and degree of injury caused by shock wave
- Hard packaging: additional explanation of fragment enhancement effect
- Typical statement: "Shock wave overpressure can cause mild internal bleeding within 3.5m"
Implementation suggestions
- The laboratory should be equipped with a detonation pressure sensor to verify the calculation results
- For composite explosives, the equivalent coefficient needs to be calculated by weight of the components
- When used in urban environments, it is recommended to introduce an obstacle attenuation coefficient (0.6-0.8)
- Regularly check the validity of the comparison table data in Appendix A
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